What Causes Equivocal Results With Pregnancy Test Kits After Withdrawal From BC Pills?

Hi I stopped my birth control Aug 1 started Aug 4th. My husband and I had sex around 15th try to conceive. The next week I had sore breast, nauseous, frequent urination. I had been starting early so I believe my period would have been Aug 28th on at 25th cycle. We had sex sept 2 and I had brown cloudly discharge than sept 4th I started to bleed blood clots and have been for 3 days now with the first day being the worst. In 3 day i probably on bleed half of a pad. I notice it s only when I wipe and they are blood clots. I took 4 pregnancy test and 3 came out positive but hrs later. Can I be pregnant still? Does blood clots count as my period? I also currently have pressure in my lower abdominal and cramps. But haven t passed a clot today