I Have A Strange Question. I Am Preganet With Triplets.

I have a strange question. I am preganet with triplets. But all urine and blood tests show up as I am not preganet. How is that possible? I look to be about 4 months along even though I am 9 weeks? I can't keep anything down? No meds work? I want to carry full twm of 40 weeks and deliver vanganially? Ty