@greenstraws23,
Did you go on any new medications in January/February or stop using one? Not just medications related to birth control but any changes to your medications whatsoever?
I agree with the others that you should get an exam by an obgyn. Make sure you ask them to rule out an extra-uterine pregnancy. An ectopic pregnancy in the fallopian tubes would have caused significant pain by now, but it is possible for a fetus to develop in areas other than the uterus or tubes resulting in lower levels of HCG that may not be detected by urine tests and low quantitation in blood tests.
Or, it may be any number of other things - all best ruled out by an ultra sound.
Good luck!