I was on the Depo for about 6 years. I stopped taking it in December 2013 and then took one last dose in June 2013 until I decided another form of birth control. The Depo would work from June until September 8th 2014. On September 17th 2014 my partner and I had unprotected sex. On August 25 2014 I had some bleeding, I went to my PCP. (I never had gotten my period in any of the 6 years I was on the Depo, During August 25th the depo was still in my system. Between January and June 2014 my periods came back regular. Then stopped again once getting the depo in June. My PCP said it was probably breakthrough bleeding from the depo) I took a pregnancy test on Wednesday this week, Friday and Saturday all were negative. Today I have clear discharged with very little pink. My breasts have been sore, I'm extremely tired and just don't feel all that well. I don't know when I ovulated. What's the chance that I could be pregnant? When to take another test and when too stop if they keep being negative.

Because of the issue of cycles, it is so hard to tell. Thus, I understand, your problem.

Normally you test two week, after a missed period. Or perhaps about 4 to 5 week, after sex