Am I pregnant

[Kait_dawn]

I lost my virginity 2/4/17 and my boyfriend didn't use a condom. I am on birth control but I was on antibiotics at the time. Well my period was due 2/13/17 and I was 2.5 weeks late, and I spotted very lightly for 3 days. Well my period for march never came. On 4/6/17 I spotted lightly for 1.5 days and it looked like dry blood that was stringy like mucus. I have had symptoms of pregnancy and I'm not sure I am. I took 5 test, 4 were negative and 1 was a faint positive but may be a evap line. I have a urine test at my doctors office but it was negative. Now I've noticed my tummys gotten rounder, it's starting to get hard and you can see my veins so bad all over my body. I've also had some cramping but if I turn a certain way it goes away. Could I be pregnant. What should I do?