Early pregnancy has me so confused 😔 TMI PIC

So little background.....I had a MC June 16, 2017. My cycles came back 40 plus days, so this past Friday, I had an appointment with my OB to discuss getting them back on track. She did an ultrasound and told me I had very thick lining and expect to get a positive test or a horrific period in a week. I ovulated on CD38 (the 2nd of this month) and had very pale pink and brown spotting 4dpo, which my OB said could of been Ib. So Saturday I had a little more spotting, came down with a nasty cold, slept most of the day then 10 hours that night. Sunday, 8DPO, I decided to POAS and to my surprise it was positive! Monday, I took another test that came back positive as well. So my problem is, here it is 12DPO, I've had 2 BFP and I've started spotting again. This time pale pink with a little bit of red. I am trying to stay positive, but this is so hard. I have an ultrasound tomorrow, which I'm not sure what they are expecting to see. Anyone else have spotting after a BFP and everything turn out OK?