Birth Control and spotting??

Okay so i got my first Depo shot back in January, and i have to go back every 6 weeks to get another shot. I didnt have my period in February. I got it this month, and i started with spotting for a week, then my actual period came for 2 weeks. And I’ve been spotting since last monday. Im so annoyed, because i wont have anything for a day or two, and then I’ll have something for the next three days. ( I was able to have sex yesterday and i was so nervous that there would just be disgusting brownish blood everywhere. Thank god there wasnt. Of course i wasnt gonna be an asshole and not warn him. He understood and assured me that periods dont freak him out. But i still would’ve been mortified if things got messy.) My doctor said my periods would be even more abnormal than they already are at first...but is this what usually happens??