The single most effective thing you can do to get pregnant is have sex during your fertile window, which spans the five days before ovulation and the day of ovulation itself. Beyond timing, a combination of lifestyle, nutrition, and awareness of your cycle can meaningfully improve your odds each month. Here’s what the evidence shows actually works.
Know Your Fertile Window
Your fertile window is six days long: the five days leading up to ovulation and ovulation day itself. Conception probability is lowest on the first of those six days and highest in the two to three days just before the egg is released. The challenge is that this window doesn’t fall on the same calendar days for every woman, or even for the same woman every cycle.
A large prospective study found that only 54% of women were in their fertile window on cycle days 12 and 13, which is when most people assume ovulation happens. Between days 6 and 21, women had at least a 10% chance of being fertile on any given day. Some women even entered their fertile window as early as cycle day 4, and others as late as the fifth week. The takeaway: a “day 14” rule of thumb misses a lot of people. You need to track your own body’s signals.
How to Track Ovulation
Two practical methods work well together. The first is monitoring your cervical mucus. As you approach ovulation, mucus becomes clear or partially clear, stretches over an inch between your fingers, and creates a sensation of lubrication. This is “peak type” mucus, and it signals your most fertile days. Outside the fertile window, mucus is either absent (dry days) or present but sticky, cloudy, and doesn’t stretch.
The second method is ovulation predictor kits, available at any pharmacy. These detect a surge in luteinizing hormone (LH) in your urine. A positive result (often displayed as a smiley face) means ovulation will typically occur within 36 hours. Testing once or twice daily starting a few days before you expect ovulation gives you a reliable heads-up so you can time intercourse accordingly.
Basal body temperature tracking is another option, but it confirms ovulation after the fact rather than predicting it, so it’s most useful for understanding your cycle over several months rather than timing sex in real time.
How Often to Have Sex
You don’t need to have sex every single day, though it doesn’t hurt. The American Society for Reproductive Medicine notes that cycle success rates are similar whether couples have intercourse daily, every other day, or even every three days during the fertile window. Success drops only when intercourse happens just once during the entire window. The sweet spot is every one to two days during your fertile days.
There’s no need to “save up” sperm by abstaining. More frequent intercourse does not lower your chances, and couples should not limit frequency when trying to conceive. The best approach is whatever feels sustainable and low-stress for both of you.
Eat for Fertility
Diet has a measurable effect on ovulation. A large cohort study of over 17,000 women found that a “pro-fertility” dietary pattern was linked to a lower risk of ovulatory infertility. That pattern looks a lot like a Mediterranean diet: plenty of vegetables, fruits, whole grains, olive oil, and fish, with less red meat and fewer refined carbohydrates.
A few specifics stand out. Replacing some animal protein with plant protein (beans, lentils, nuts) was associated with improved fertility, particularly in women over 32. Monounsaturated fats, the kind found in olive oil and avocados, appear to reduce inflammation and are positively correlated with shorter time to pregnancy. Omega-3 fatty acids from oily fish or supplements support egg growth and maturation and are linked to more regular ovulation.
On the flip side, diets high in refined carbohydrates and low in natural fats were associated with more ovulatory problems. Swapping white bread for whole grains and choosing full-fat dairy over low-fat versions aligns with the patterns that performed best in the research.
Start Folic Acid Now
The CDC recommends that all women capable of becoming pregnant take 400 micrograms of folic acid daily. This doesn’t boost your fertility directly, but it dramatically reduces the risk of neural tube defects in the baby’s brain and spine. These structures form very early in pregnancy, often before you even know you’re pregnant, so starting a prenatal vitamin before conception is the whole point. If you’ve had a previous pregnancy affected by a neural tube defect, the recommended dose jumps to 4,000 micrograms daily under a provider’s guidance.
Weight and Fertility
Body weight affects your chances of conceiving in both directions. Research using national health data found a U-shaped relationship between BMI and infertility: being significantly underweight or overweight both increase risk. The inflection point was around a BMI of 19.5. Below that, each unit increase in BMI reduced infertility risk by 33%. Above it, each additional BMI unit raised the risk by about 3%.
The mechanism differs at each extreme. In women with very low body weight, the body may suppress ovulation entirely as a protective response. In women with higher BMI, excess fat tissue can disrupt the hormonal signals that trigger egg release. Even modest weight changes in either direction, moving closer to a normal BMI range, can restore regular ovulation for many women.
Limit Caffeine and Alcohol
You don’t have to quit coffee entirely. The European Food Safety Authority recommends keeping caffeine below 200 milligrams per day when trying to conceive, roughly one 12-ounce cup of brewed coffee. The World Health Organization sets the threshold slightly higher at 300 milligrams. Staying under 200 milligrams is the more cautious approach and easy enough to manage if you’re aware of hidden caffeine in tea, chocolate, and soft drinks.
Alcohol is best minimized. Heavy drinking is associated with longer time to pregnancy and more ovulatory irregularities, and since you won’t know the exact day conception occurs, keeping intake low protects early development too.
Your Partner’s Habits Matter Too
Roughly half of infertility cases involve a male factor, so your partner’s lifestyle is just as relevant. Sperm count, motility, shape, and DNA integrity are all sensitive to everyday habits.
Smoking damages sperm DNA and is linked to lower semen volume and reduced sperm counts. Excess weight in men lowers sperm production through a hormonal chain reaction: fat tissue converts testosterone to estrogen, which suppresses the signals that drive sperm creation. Over time this leads to reduced testosterone and fewer sperm.
Heat is another underappreciated factor. Sperm production requires a temperature slightly below core body temperature, which is why the testes sit outside the body. Prolonged sitting, hot tub use, laptop computers placed on the lap, and high-intensity cycling all raise scrotal temperature enough to impair sperm production and damage sperm DNA. Simple changes like taking breaks from sitting, avoiding hot baths, and keeping electronics off the lap can make a difference.
When to Get Help
If you’re under 35 and have been trying for 12 months without success, it’s time for a fertility evaluation. If you’re 35 or older, that timeline shortens to 6 months. For women over 40, earlier evaluation is reasonable. And if you have a known condition that affects fertility, such as irregular or absent periods, endometriosis, or a history of pelvic surgery, there’s no reason to wait at all before seeking an evaluation.
A basic workup typically involves bloodwork to check hormone levels, an ultrasound to look at your ovaries and uterus, and a semen analysis for your partner. These tests can identify straightforward, treatable causes that might otherwise cost you months of frustration.