Implantation Bleeding??

This post will be kind of long but I want to be specific.

Okay so this is my first month without the IUD Mirena. i had the IUD removed the 6 of this month. Usually BEFORE I had the IUD in place my period would always be around the lasts or firsts days of each month. AFTER I had it removed I got my period the 8th of this month. I think had I removed it a week before my period would have came the same days. My husband and I have had unprotected sex the 14th, 15th, 18th and 22nd. I ovulate the 21st according to the app Flo and according to Glow i ovulate 22nd. So this week as well I have been feeling very nauseous, a little back pain, sometimes dizzy and today I noticed I had blood. but not like my period it was lighter in color. i have very little cramping not like the usual I have for my period.

Is it implantation bleeding or is it my period? and are the symptoms caused by my hormones being all over the place because of the IUD?

Thank You so much in advance ♡