Could i be pregnant or is it just me being weird ?

Me and my Boyfriend have been going out for about a year now. Litterly love him to death. We've stated having sex recently,I lost my virginity to him. The sex has been great and mind blowing. So this weekend we were messing around and had sex on and off lying in his bed talking or watching videos on youtube then right back to it mainly. He wore a condom but he later took it off and we just did it that way for awhile and he pulled out and came when he got to that point. We've done this a lot before but now this time I'm home in bed and my stomach hurts and I'm kinda bloated. I'm kinda scared now did he have like pre cum that got in me or some got in me. This has happened before just not with the pain and my period is due in a few days so its probably that but idk. So why am I feeling this way idk