My period for this month lasted 5 days. My boyfriend and I have had sex in which he has ejaculated inside. We recently had sex 3 days ago and I am supposed to ovulate tomorrow. I've read you can get pregnant having sex days before or after ovulating. As to 3 days ago, I was fertile. Could I be pregnant

Yes, also, how do you know when you are ovulating ? Online charts are estimates, so unless you are doing medical test to determine dates, you really do not know.

Since it can take 2 or 3 days for sperm to reach egg, doing it 2 or 3 days before, is correct to conceive

ANY time there is penile insertion, there is the possibility of pregnancy. So yes you could be pregnant. But there is no way for us to say one way or another. The first physical manifestation of pregnancy is a missed period. If you had a period in July, then you need to wait until your period is due in August and see if it comes. If it doesn't you wait another 2 weeks and you can start testing.

There is no point in asking now as the only answer that can be given is yes you could be pregnant because you had intercourse.