Late period

so my period is 4 days late and I’m low key freaking out.. me and my SO did stuff a couple weeks ago without a condom but we didn’t have sex but his dick was all up on my vagina but he never stuck it in.. if that makes sense. He never came inside me.. last week we did have sex without a condom..(stupid, i know) but he pulled out and I’m 96% sure he didn’t cum in me but i got a plan b anyways.. i took the plan b a day after i was supposed to get my period which was within the 72 hours post sex. however my period is 4 days late and I have mild cramps but they are VERY MILD.. im scared 😩