Depo Shot didn't work?!

Shasta

I had my first baby on July 3rd 2017, and I just got the shot earlier this month (on September 15th). However, my hubby and I have had unprotected sex about every other day since I was about 4 days post partum (PLEASE DON'T JUDGE, I'M LOOKING FOR AN ANSWER TO MY UPCOMING QUESTION). My post partum bleeding stopped after only 2 weeks post partum. I haven't bled or spotted ever since. I have been feeling like I did before I found out I was pregnant with my first, for like a month and a half now.. I constantly have to pee, I am super nauseous like all the time, I have been vomiting, I have diahrea, I am super tired (my baby sleeps all night, so there is no reason I should be tired seeing as I sleep when she does), I am in this bitchy mood all the time, I only want sweets (but cant really stomach anything aside from pizza, fries, and soup), and I cry at everything. With my first, I tested positive on an ovulation test and negative on a pregnancy test on November 3rd, 2016. I was positive on both a pregnancy and ovulation test as of November 5th, 2016, and that's how I found out I was pregnant with my first. Well, today I decided to finally test, and I got a positive ovulation test, but a negative pregnancy test. So I guess my question is, what do I do? I was five weeks along with my first when I found out (I always have irregular periods so I never know). I haven't breastfed since August 2nd.