Period restarted after sex?

I (26F) was on my last day of my period where it was that brown spotting on Sunday. My boyfriend and I had sex on Sunday now since then my period seemingly restarted. It’s pretty light and no pain, but it’s red blood again so this is technically day 10. A little background, I have an IUD and this is the first time I’ve had sex in almost a year because my bf just got back from an overseas deployment. Should I be worried??