Missed Period.

I missed my period 4 days ago and that hardly ever happens. i’m extremely regular. my boyfriend got on this app last night i guess to just check and he found out i’m late. he says he thinks it’s because of stress but my body has been acting weird and responding to things weird lately. and there is one time i remember a while back where he pulled out but i feel like it might of been a bit late when he did. We talked last night and if i am, everything will be okay. he works and i live with him. he said i only needed to worry if he hated working which he doesn’t. i’m just scared and can’t help but worry.