Last month on the 2nd I started my period and towards the end on the 6th I had sex for the first time. My periods are usually 4-5 days. Unfortunately there was no condom, I took the Plan-B pill about an hour later. I missed my period and it's been a week after since I was supposed to have my period. I usually never have regular periods because I stress a lot and am super active. Should I be stressing? Should I get a test? I'm scared and I don't know what to do