Period come in?

So am exclusively breastfeeding. Had csection. Had lochia for 3 weeks...then again at 6 weeks some light bleeding. Was confused if it was my period or from me over working my scar. Anyway. A month+ ago, I got contraceptive injection. Was told I would bleed 3 weeks but nothing came. But now started bleeding more than 6 weeks past. Wondering if it is my period or if I strained again. Because I had some abdominal pain too before the bleeding.

Please try to understand that my husband is currently away n I have to do so much alone n despite telling myself to take it slow, some days I end up strained.

Ps. 4 months pp