Advice please - Possible implantation bleeding?

Hello, I'm new here and wondering if anyone can offer some advice. I stopped taking the pill just before Christmas after being on for 7 1/2 years (9 months on Cerelle, cerazette before that - didn't have periods while on the pill). We wanted to wait to TTC until after a few cycles. Got 1st period at end of January, 29 days after coming off the pill. I then had a 27 day cycle followed by a 28 day cycle so I thought I was lucky and things were working as they should.

My next cycle was only 17 days long with a 3 day period (usually 5) but I thought this might have been down to stress as we were moving house. Hoped my next cycle would go back to normal but I'm now on cd39 and had 2 bfns so far and going mad. I thought af had started on Friday afternoon but it wasn't much and lasted 2 hours, nothing since. Could this have been implantation bleeding? If so when I am best to test again? I don't think I have any other pregnancy symptoms, we last dtd 11 days before my bleed on Friday, and I remember having ewcm that day.

Sorry for the long post! I'm just very confused so any advice would be very helpful! Thanks