I got pcos but found out I'm pregnant but.....

I was diagnosed with pcos based on my physical symptoms *thick manly hair facial and leg hairs, irregular periods anywhere from 35-50+ days apart* I've had tests done to find out if I have any sort of thyroid condition and my test all come back normal except for my progesterone level being low and testosterone level being high which is causing the excessive hair growth. so my gyno suggested I lose some weight for starters, which I have done in the past year I've lost about 15 pounds which isn't the most I've lost before... my weight fluctuates up and down.. sometimes I lose and sometimes I gain all depending on my stress level (I lose weight) or depression (I gain weight) anyways to make a long story short I took 4 different pregnancy test all came back positive in less then 3mins went to the e.r. due to unbearable uterine pains mainly on the left side. the doc at the e.r. ran a few test for infections and pregnancy all came back negative.. I don't have any infections but their test comes back negative??? then the doc requested that I get an ultrasound done. had a transvaginal ultrasound as well as ultrasound on the uterus. they didn't find any sac or anything abnormal except that my endometrium lining is thick.. but didn't tell me how thick it was.. I might want to add that one of the pregnancy test that I did take that confirmed my pregnancy is a clearblue advanced pregnancy test that provides the positive and how many weeks you are if you are pregnant... the clear blue test stated I am positively pregnant and provided me with a window of being 1-2 weeks pregnant meaning I'm just about 3-4weeks estimated. but why is the hospitals test showing I'm not and the utrasound doesn't show anything.. is it cause I'm too early to even have a sac or could an ovarian cyst cause a number of different brands of pregnancy test to come back positive? (which is a rarity but according to american pregnancy association it is possible) which I find is odd cause the ultrasound tech and doc didn't find any cyst as they view the ultrasound neither did the radiologist state anything out of the ordinary other then the thickened endometrium lining.