Baby Measuring small and spotting

Dee

Hi

I have attached my BBT which shows that I ovulated at the latest the 12th of July. This would put me at at least 6 weeks 1 day.

I had some red blood on the toilet paper last night and a few drops in the toilet as well as some light red on the paper early this morning and nothing since. so had my HCG checked which went from 19 (21st July) to 42490 (10 Aug) and ultrasound showed a heartbeat of 125bpm but said baby was 1.8mm measuring 5 weeks 3 days. That would put conception at the 18th of July...3 days before first positive test which is impossible. Has anyone else had baby measuring small or bleeding and all worked out ok?