My boyfriend came in me so many times but I'm not pregnant?

I just don't understand 😥 I know it's only been 7 months but we've had sex a lot without even thinking about a baby we just enjoy it I take vitamins I eat healthy I try so hard not to think about it the only problem is I'm not sure when I ovulate my periods don't come every month if I'm stressed I'll skip a month. My last period was July 12 I had one also may 20th. August nothing This month I don't have anything pregnancy test at doctors came up negative yesterday. I had sex last week also so I know testing now is too early. Ughhh im just tired of waiting.