What Causes Slight Bleeding With Sore Nipples And Constipation?

Hi, I am currently trying for a baby. I have only been off the pill since the beginning of May, after I had just finished a period. A few days later, I bled again. I have had unprotected sex a couple of times and I now feel bloated, constipated, my nipples are becoming more and more sore. I am also weeing a little more than I used to. I know it s quite early. I have done a few pregnancy tests and they have both been negative. Ovulation tests have also been negative, so I don t quite know what the think. Could the body changes be due to coming off the pill? I didn t have these symptoms last time I cam off the pill though. Thanks, Kelly.