Getting pregnant with PCOS ??

Ash
Me and my partner are TTC I got diagnosed with PCOS. When I was 16 now 21 almost 22 I have been getting regular periods since January having a 20/21 day cycle I was due for my period yesterday the (28th) but still hasn't come normally exact on day and took a pregnancy test 3 days ago (26th) but it came back neg :( I have been getting really weird almost butterfly feelings in my stomach and cramping on my lower left abdomen as well as very sensitive breasts ??? Has anyone else had this and found out they were I fact pregnant ??