I miscarried on the 18th jan at 15 weeks

I started my period on the 16th feb for 6 days

I’ve had really uncomfortable lower back pain for the last 3 days and then spotting today.

I’ve never spotted from ovulation before and am not due to ovulate til the 2nd March if the calendar is correct and my opks show I haven’t hit peak yet

Any ideas? Just looking for some advice or insight thanks