Period lighter and shorter after sex, is this normal?

I recently started having sex again in the beginning of January after about 3 years of abstinence and noticed my period has been a lot lighter. I usually get my period for abt 4 to 5 days and it’s usually heavy on days 1-3. I also always get bad cramps on day 1. My period came in January and it was a lot lighter then normal, no really heaving bleeding at all and only really lasted maybe 3 days. I got my period again in February, on time, and it’s also very light and stopped for a day then came back again but was still light, no heavy flow. I did still get cramps on day 1 too. I will note i have been having sex regularly and did have sex on the day my period started in February. Is this normal? I haven’t experienced this before and i did take a pregnancy test and it came out negative. I’m also currently not on BC anymore for about 2 years now, but i used to be on the Depo shot and that completely stopped my period in the past when i was having sex so i can’t say i’ve experienced this. Im just nervous about this and concerned, has anyone else experienced this??