Confused by my symptoms and opposite test results!

I'm DPO 13 and I just woke up an hour ago thinking I had to throw up. I didn't end up doing it but I'm so nauseous that I can't fall asleep because I feel that it's right there. I never throw up and haven't in over 14 years. This past week, I've feel really tired, bloated and I had very sore, tender nipples. I took a test on Thursday and was BFN and one Friday and was BFN. AF is supposed to be arriving today. I don't feel like myself at all yet I keep getting BFN's!!! Anyone have any advice?