nausea before BFP?

Ni
Has anyone had nausea before they got their BFP? AF was due two days ago, but it's pretty normal for my AF to be late or not show at all for months at a time due to my PCOS. I had a little bout of nausea yesterday but had already took a preg test that morning with first mornings urine and got a clear BFN so I didn't think much of it. But again today the though of the lunch I just ate (which was good while I was eating it) made me so nauseous. I then tried to go to sleep thinking maybe I was just coming down with something and every time I closed my eyes the food I just ate would pop in my head and I would sit up with a watery mouth about to puke. Needless to say I didn't get to take a nap and instead grabbed a pregnancy test and tested. The pic above is the pregnancy test I just took midday. My urine was severely diluted due to me chugging water all morning but still it's a clear negative. I was always under the impression that if you were showing symptoms of pregnancy that the hormone level should be high enough to get a positive at home test. Is that true? Prob just a fluke thing or I am really just coming down with something. Just wondering if others have gotten a BFN after having morning sickness but ended up really being pregnant.