So I had my depo shot november 14th 2016 .. I always have a period whej im due for my depo shot . Every 12 weeks your supposed to get your depo shot . Now it has been 15 weeks since my depo shot and no period so i am late for my depo shot ive been having sex and still no period ive took 2 pregnancy tests 3 weeks ago it was negative . Today i had sex and it was a smell of blood but no blood. What does this mean?