Could this be a sign that i am...

So I had unprotected sex Feb. 14th and he pulled out, then we did it again on Feb. 24th and he came in me. 4 days later on the Feb. 27th my "period" came 2 days early which never happens, and it lasted 5 days like usual but was much lighter and I did not have any clots like usual so that was weird. And of course I've got all the PMS symptoms like backache , headache, mild cramping but im not bleeding anymore and still have these symptoms. You think there's a chance i could possibly be pregnant?