I had a similar thing happen with DS. I got my BFP at 12dpo, I normally have a 12 day LP. That evening I started spotting. Mainly brown. It continued for a week. I had it again at 6 weeks then a bleed at 14 weeks. I now have a very bright & bubbly 15month old.

It is a common thing. I had my HCG levels checked every few days. They were rising beautifully so I knew everthing was ok. If you are concerned, tell your GP & order a series of blood tests.

Congratulations on your BFP!