Irregular periods after mc, no af yet, bfn. Did I ovulate?

AF is 7 days late, I've tested on the day my period was due and 6 days later and got BFN both times. I miscarried in Feb this year and since then my cycles have been irregular. Prior to mc my cycle was regular and 28 days, post mc I've had irregular cycles - first period cake 6 weeks post mc, then 35 and 27 days. I'm now on CD 36, no af. I also took an opk today and it turned out positive I think? So confused with what's happening, anyone out there who's had similar experiences and can shed some light?