Advice help (please read )

Me and my boyfriend just had sex and I think he might of cum in me and I don’t know what to do I am on birth control I take the pill but right after we had sex it was nice but it’s painful whenever we have sex but I don’t want to ruin the moment so I don’t say anything but I feel really like nausea and I keep like farting and I have some stomach pain is their a chance I could be pregrant I really hope not ... I also feel sore my mom will not be happy at all .... I’m scared and anxious please leave comments