8 days late and a negative...?

So I was sure I was pregnant... Sore BBs and they are a little enlarged, Ive been sick to my stomach off and on throughout the day and have vomitted twice, constipated this week and I have had two dizzy spells that I never ever have. And my period is 8 days late... Well my cycle is anywhere from 25 to 28 days but lately its been 25 so im 8 at the most and 5 a the least late. I had basically everyday during the week I would have ovulated regardless of the cycle I based it off... I am very stressed out though lately... I just tested at noon and got a negative... Its the first time i tested since like 5 days before my period was due which was a negative. Any ideas? I know monring urine is the best but i figured since i was so late it wouldnt matter and with my two daughters i tested at 9 dpo and got a positive in the afternoon. Thanks for any help or advice