I am a week late on my period now and believe i am getting pregnancy syptoms, have had slight nauseous feelings, extremely tired all the time and headaches. Done 2 tests, 1 four days ago and 1 yesterday, both negative. I started taking fluoxetine a couple of weeks ago so im in limbo as to whether im pregnant or is the fluoxetine affecting my periods. Dont know what to do! Help please!