Confused!?!

I have got a faint blue line on a pregnancy test. (I know they’re known for false positives.) but the next two times I took them they got darker and darker. Last night I took a pink strip test and yep there’s a line. Today I took a strip test and there is absolutely nothing!? Am I have a chemical pregnancy test? Was I never pregnant and just some how had four false positive test? Am I just early? This is so nerve racking.