Needing Advice

​I am feeling so confused these days and really need some guidance. My husband and I have been TTC for four months. This past cycle we BD on all the right days and I had light, dark brown spotting 6&7 DPO. Since then I have had sore heavy breasts, nausea and vomiting, exhaustion, etc. AF is now five days late (I have never been late, nor have I ever had mid-cycle spotting) and all of my tests are still coming back negative! Could it be the batch of cheapie tests I got on Amazon? Could I still be pregnant? If I call the doctor, what do I even say to get an appointment? Thanks for any and all advice- I truly appreciate it!