Spotting day 20 :(

I've been taking clomid a while ( did get pregnant in between had mc) . I took my first round and every thing fine but then last month on day 22 I started light bleeding nothing like normal . Was waiting for heavy so I could start clomid but never happened so missed my chance now it's happened again this month . What's going on so frustrated . Normally like clock work , 28 day cycle . Heeeeelp :(