Is there a chance I'm pregnant?

Yes I know my name is "baby mamma 7 weeks" but I'm not really sure. I took 2 pregnancy tests 3 weeks ago both were negative but I am having symptoms. I always feel sick, peeing often, head aches all the time, bloating ect.. I had unprotected on January 29. I haven't started morning sickness yet but I am 7 weeks and 3 days. Should I take another test? Oh by the way I'm 13 so I don't know a lot about this and I don't have money to be buying a whole bunch of tests.