implantation bleeding?

Shelly
I took a 3 pregnancy tests last week and all were positive. I also got a blood test which was positive as well. I conceived around October 13. The past 3 days I've had some spotting. First day was brown, yesterday was pink and today is brown again. Is it normal to spot this much? It's not a lot but every time I pee it's there when I wipe. I know spotting is normal, just didn't know if this many days is normal. 
I have a doctors appointment this coming Tuesday, but seeking any advice prior. I'm kind of worried. 
Thank you in advance.