Hi.. For the past two weeks I have been feeling weird. At first I could not sleep and would be up all night and then I started to feel exausted to the point of not wanting to get out of bed. Then that went away and I was only able to sleep in spells and I would always wake up around the same time in the middle of the night and I would be hungry. Then I started getting nausea but just burping and soon after that I started getting pressure headaches along with the nausea and this acid reflux burning sensation in my throat and I have had sex when I believe I was ovulating but only once but I just got my period but I keep feeling nausea and headaches and I took a pregnancy test before my period and got a negative what could this be?