Possible Pregnancy?

So I was on the Nuva Ring for 1 Month almost 3 months ago. Well, I got Two periods afterwards(I stopped using it after 1 month try). Well my last period was July 1st. I had sex around July 8th and July 17th both time unprotected and he did finish inside me(my husband FYI). Well, July 20 I had Light brown Discharge not enough to get into my underwear. It lasted for about 3 days.. It was stringy TMI sorry.. Like Uterus shedding. It stopped and since then I have had lots of thick milky mucus. I took a pregnancy test right after the brown discharge stopped and it was negative. Well, my next period is due August 1st. I know pregnancy is possible. We have one child together and I found out 5 days of missed period I was around 5 weeks pregnant with him., I couldn't stop peeing that was my only symptom. I have only had a really bad headache I can't seem to get rid of on and off for the past week. Opinions? Could this just be my cycl being screwy?