Am i pregnant? please only serious answers?

i am on Yasmin birth control and may have missed a pill or two about 2 weeks ago. The past week i have had constant headaches and stomach aches (sick to my stomach too) this week i have also been urinating very frequently. Once i go pee 5 minutes later i have to go again, especially if im walking around. and this morning i ate breakfast and threw it up ad have been extra tired and have to take a nap during the day. I took 3 home pregnancy test throughout the past couple weeks and all are negative, do u think i could be pregnant and its too early to tell? i have a doctors appt on the 13th, should i get a blood test for pregnancy?