AF...blah(tmi warning...)

Theresa • 26, TTC going on 5 years. angel mommy to 4 babies after the last 2 out of 4 IVF rounds worked(kinda) M/C @ 4 & 5 weeks
Ever since my second miscarriage in March my cycles have been weird. No AF April or May. Really light in June & now July-this month I have a normal AF & then a light flow day 13/14 that last on and off about a week! What can cause this!?!