What is going on?

Started bleeding (not my period) finally stopped after 2 days, felt really naseous for past 5 days, took a digital hpt came out pregnant. Waited til following day and took several more (all negative) went to Dr..couple of days later, blood test came out negative. Now for the past 4 days have felt like I was on my period, cramps, bloated, sore breasts...etc still feel naseous, fatigued... and yet, no period... Dr. said I would have miscarried but only being 5 weeks or less, would 't have known I was even pregnant....  I feel pregnant.. could the blood test be wrong? Could it have been too soon??? What is going on with me? I've already had 2 kids....and I FEEL pregnant. Is this normal after a miscarriage????