I'm 17 years old and sexually active. I have been lactating, my breasts constantly itch, craving things I usually wouldn't eat, always sleepy, headaches, and dizziness. Also I had no period the whole month of March. Instead of gaining weight, I've lost a couple pounds but thats normal with women in my family during pregnancy. If pregnancy tests with urine are negative and prolactin levels are normal, is it possible I'm still pregnant? How can I get an accurate answer?

I'd recommend seeing a Gynecologist... even if you are a month pregnant... you shouldn't be lactating yet. Its possible to test negative on the urine test (even if you do it right) and even the blood test and still be pregnant... its not common, but its possible.