Me and my boyfriend have been trying to concive. So every time we have sex he doesn't pull out. This has happened mor than 20 times & I'm still not pregnant. Does this mean one of us is sterile?

There can be many reasons you haven't conceived yet. There is no way for us to say whether sterility is the issue. You should be discussing this with your OB/Gyn who can order the proper tests.

So you are tracking your fertile days, and have had sex over 20 times on just those days, being sure not to have sex prior to the fertile times to build up his sperm count more.

But while some and many people get pregnant the first time, many issues fall into this and some couples have to try over a year, and are having to track the best times to have sex.

Far too soon to worry about one of you being sterile. As was said, it can naturally take many months of trying before you become pregnant. Doctors usually don't even start initial fertility testing until you have been actively trying for at least a year. And actively trying means having already taken steps to determine when you are most likely to be ovulating in a cycle.

It would be wise to see your doctor for a preconception visit and discuss the various ways to get an idea of when you are most likely to ovulate. There are numerous ways from tracking cervical mucus, checking for cervical position changes, using an ovulation predictor test, tracking temperature changes, etc.