Period problem PLEASE HELP

I haven’t had sex in three months, the first two months after the last time I had sex my period came on and everything was fine... now (on the third month) my period is EXTREMELY light and I’ve never had a light period before. I only see blood when I wipe and a little bit on the pad. This happened about 4 days after I was supposed to get my period. (According to the app) WHAT DOES THIS MEAN ???