If I were you I would wait a week or two, and if you don't get a period in that time... test again. If you still have symptoms and the second test is negative, go to the doctor and get checked out.
You just may not have enough hormones built up in your body yet to produce a "positive" result. But, you could just be having hormone and body fluctuations do to coming off of the birth control and stress.
In the meantime, don't do anything stupid... if you are smoking or drinking- quit... don't take any medications that you are not supposed to... DO take a multivitamin everyday and bulk up on your healthy foods. you know, common sense. That way you won't be kicking yourself if your test in a couple weeks comes back positive!
Your doctor will not (should not) think you are a "nut" if you think you are pregnant, but are not. She will probably be happy that you took control of weird body "symptoms" and paid attention to them, rather than just ignoring them. Since you have been pregnant before- you do know what it feels like, so that is even more reason to be careful!
Good Luck to you and "yours" either way!
-M.