Spotting/3 weeks pregnant

So recently I had taken a at home pregnancy test it came out positive, when to planned parenthood took another and received two negatives then took a blood test. Results came in this morning and I'm 3 weeks along. I know I found out very early, but I've been spotting and cramping for a few days..today the bleeding seemed to get a littler heavier than just spotting..I'm not sure if this is normal.. Please any advice is welcomed!