2 months late on my period. Ive taken 4 HPT but there all negitive. Could I be pregnant?

I usually get my period around the 10th every month. In april I took a plan b the first time me and my boyfriend had UNprotected sex. The plan b messed with my period and I got it again April 23rd the next day. So for the month of April I had my Period twice. It is June 28th and still no period. ive had spotting once and nothing since. My discharge has increased although it doesnt smell. Ive taken 4 HPT in the past 2 months and they were all negitive. The dr recominded I start birth control and to go back in a month for another test. But I dont think that is the safest thing to do if I am pregnant. I want to take a blood test, but I dont know how to go about this. Any advice?