Really light/brown first day of period?

Hi guys, I am a little paranoid in general but especially this period cycle, I was a day late (not super uncommon for me) but my period is super light and the blood is brown. Usually it’s bright red and I’m cramping like crazy. Day 1 had some cramps, but I usually need Midol to fall asleep night 1 but I didn’t even need to take anything yesterday the whole day, cramps were super manageable.

I switched medication doses recently—usually on 5mg Lexapro, but 3 days before period started I ran out of pills so couldn’t take for 2 days. Then the day before period I started taking 7.5mg (as per my new prescription) and have been taking for 3 days now. So timeline is no meds 2 days, 7.5mg 1 day, period starts next day while on 7.5mg. Is this change normal? Are these side effects too soon after switching doses?