Maybe you ovulated late so would have your period-gotten pregnant late? Try a first response test in a couple of days they have a good report for picking up small amounts of hcg in the urine if that still neg and no period maybe visit your doc. Good luck
About a year ago when I started to TTC with my husband and I took myself off of birth control I had the same symptoms and no cycle for months. After all of the pregnancy tests and blood work being negative the dr. found that I have PCOS. I’m not saying you do, but, it’s a good idea to make that appointment and find out what is going on. If anything the dr. will give you meds to give you a cycle. I hope all goes well. Good Luck.
Sometimes it is very possible to "trick" your body into thinking your pregnant and all those symptoms are signs of pregnancy as well as periods.... If your tests are negative right now you can wait a few more day's and try again or go to the Dr. and get a HCG beta test done. Although, sometimes those are not alway's accurate either. My HPT's with my first child were all negative, and so was my beta test until I was almost 4 months along with him.... Good luck