I want to get pregnant.. HELP?

So my boyfriend and i have been having unprotected sex since we first started having sex, and back in February he nutted in me for the first time which scared the hell out of us since that was the first time we ever let that happen. We started eagerly planning for a positive result on the pregnancy test since no one really knows if they are or not. It came out negative and it was a bummer. It's been two months and ever since then we've actually been trying to get pregnant but every month that went by I always ended up with my period and it got to the point to where I cried about it. I just turned 21 years old and my boyfriend is about to be 19 in July. I see all these girls I knew back in high school getting pregnant like it's so easy but for me I don't understand why I haven't. People are usually so careful with sex and use protection and somehow still get pregnant, whereas I do not take birth control or use condoms and nothing has happened. So my boyfriend and i have been doing our research to see if maybe one of us are incapable of having kids. For him, he is healthy, he has a healthy diet and works out frequently and his thick and gooey sperm (from my research) is normal. So I started to look into it being me. We've noticed that when he cums, it doesn't stay in Me, no matter how we approach it. I've even kept my legs up and he's even stayed in to make sure it doesn't spill but it still does. On his research he found that i could possibly have a thin canal that prevents the sperm from going in correctly. In my calendar on here I ovulated on the 21st (that week was my fertile window), and we happened to have sex the afternoon/evening before. Here's the problem though; we had just smoked a fat blunt and were stupid high (it was 4/20, duh) and I thought I swore I felt him cum but that time it didn't spill out like it usually does... plus he said he was so high that he couldn't tell if he did cum or not. So my question is (sorry for the rant), if he did come, is it possible I could be pregnant with the fact that i ovulated the next day? And if he didn't cum, does weed effect ejaculation at all? Could the weed have effected my canal to open up maybe? HELP!!! 😭😭😭