A period or something serious?

We discovered at my 14 week appointment that the pregnancy was not successful. Fetal death was measured at 10+3 (days after I heard the heartbeat for the first time). I had a d&c three days after the appointment. Everything went smoothly. Afterward, I barely had cramping and some light spotting that’s been lasting longer than expected. Last night I woke up in the middle of the night to a lot of blood and had to change my tampon from a few hours before. About three hours later I had to do the same. It’s been 12 days since the procedure. It’s not at the level my doc said to be worried (going through a pad an hour). It seems like my period may have started earlier than expected. Does anyone have experience with this? I don’t want to go to the ER if I don’t have to, but also don’t want to ignore if it’s more serious. There’s no real pain, other than what feels like light period cramps.