Implantation bleeding?

I'm on day 30 of my cycle with no period. I took clomid at the end of January and ended it the beginning of February. I had sex every other day for 10 days like instructed and went for my progestrone test on February 13th, the doctor called later that day and told me my level was 35.5, which is high for me, I'm normally at 4 or 6. They told me to test next week (this week) and call them if I get a positive test or a period. I've been really tired and hungry all the time and my breasts have been hurting extremely bad, like they are impossible to even sleep on them. I went to the bathroom today and had a very little amount of brown discharge. I am supposed to go to the doctors tomorrow for a blood pregnancy test. Is it possible this is implantation bleeding? And if so will I recieve a positive test tomorrow?

A little background. I have PCOS and I got pregnant March 2016 and miscarried in May, I did have implantation bleeding with that pregnancy but I had just thought it was a period since mine are so irregular and are never consistent. After my miscarriage I haven't gotten a period since, so this brown discharge is the first thing I've seen since.

My husband and I have been trying for 2 years and I was really getting my hopes up that I was pregnant.

Advice and information would be greatly appreciated! Thank you!