Pregnant?

It says im on cycle day 47 since i last had my period on february the 17th. I took urine and blood test. They came out negative. My nana told me to wait and see if i skip aprils period cycle. I am taking lithium and that might mess my hormones. But ive never in my life skipped a period. And my bf and i have been having sex while i ovulate. I have been having alot of discharge. Nausea as well and feeling very tired. Id think its lithium but the sidebeffects dont lastbup to a month. So i find it wierd. I also feel very hungry. Get minor cramps but no period. I hope i am pregnant :(. Just very impatient to wait till the end of month to take a blood test and probably make a doc app to get an ultra sound. Ive been hearing how sometimes tests can be negative yet people are pregnant. So i want an ultrasound.