Sounds like you have mid cycle spotting. It is not related to pregnancy. If you had your period 2 weeks ago, you'd only just now be ovulating.
Not being able to lay on your stomach is not an issue in pregnancy until you are extremely advanced into the pregnancy.
Wait until your next period is due and if it doesn't show up, take a pregnancy test. If it does show up, thank your lucky stars and get on some birth control.