A couple of weeks is a little too soon to tell especially with HPT's. You said you've had blood test so I would wait on that. When I first got pregnant with my daughter I was not ever nauseated, never had any "signs" of pregnancy. It wasn't up until taking test after test about 4-5 weeks later that I finally proved positive on an HPT.
On the other hand I've also had the extremely painful tension headaches but that was because I kept thinking too much about what I was going to do, and how life would pan out having a child. Perhaps, if you aren't pregnant and have yet to get you period then take a bubble bath, go get a mani-pedi, do something that you know calms you or relaxes you because don't forget...stress can also make a cycle irregular.
Hope this helps. Let me know if you are pregnant, having someone to talk about how you feel about this stuff can help a lot. Or even if you're not pregnant. It's funny talking to strangers but I've found it incredibly helpful.