Cramping , lower back pain , and PCOS

Hi! I am a 27 year old female and for the last couple of months now my fiance and I have been trying to concieve. For about a week a a half now I have no been feeling well. I did go to the doctor and they ruled it out as a viral illness. My last period was last month on the 1st, my fiance and I had intercourse on the 7th. Right dead on the 7th of this month I started to get sick. It started with a headache and dizziness and was followed with nausea, diarreha, sensitivity to smell, fatigue, and headaches. I did vomit and it was 2x a day. The symptoms have subsided a little but last night I had a huge headache and the nausea came back. I took a HPT on Monday and it was negative. But with PCOS it can be negative but you can be pregnant and can be a positive but be not pregnant. I asked the doctor to do a blood test and she said that they do a urine one first, this was even after she knew that I had a negative HPT test on Monday.

My sisters all say it is in my head but I have no felt like this before and its been driving me crazy. Can anyone help me out here?