Boyfriend cam in me for the first time.

Okay I know this may be a little tmi, but I'm on birth control and I have been for about a year now, and just Thursday night my boyfriend decided he wanted to see what it was like to cum in me. (we've been together for 2 years and plan to get married once I graduate college) So being on birth control I said sure. I mean I know there's still a bit of a change but not too high. And I was told before by friends that a lot normally comes out of you after it goes in. But none came out... at least none that was noticeable. And now I'm slightly wondering what the chances would be that I could get pregnant. I'm not suppose to have my period for another like 2 weeks but I'm still slightly nervous. Any thought?

Update kinda thing:

Also, does it matter if my periods are irregular? Like I started my period like 2 weeks early last month and I assumed it was because my sisters and mom started so like our periods linked up. And I'm not suppose to start for another 22 days, but I just started bleeding some today. Does this mean anything?