Could I be pregnant?

I’ve been on birth control for a year now and my boyfriend came back from a month long trip last night and we had sex and it was the first time he came inside me we always used the pull out method. now I know I should be okay because I take my pill every day at the same time and have had occasional late pills the last time I took a late one was a couple months ago but I can’t help to over think, today I’ve been having stomach cramps and discharge I’ve never had anyone finish inside me he’s my first and can anyone tell me what I should do after he finishes inside I was kind of shocked and made a mess everything just came out after he pulled out lol