Test negative then positive?

So this is kind of confusing and probably not worth asking.. however, a few days ago I was extremely nauseous and experiencing strange symptoms. Since my daughter (1 yrs old) was an unexpected baby, I’ve become a serial pregnancy test taker. I take a pregnancy test every month basically because my period is almost always late. A lot of pregnancy tests will say negative and end up being ‘positive’ after a week or something as the dye line shows up. I know all of those were negative because the line doesn’t look exactly right and it’s just from sitting like that. However, about 4/5 days ago I took a test and it looked negative, but now there is definitely two lines. Which I know, I know, probably a dry line, but this is the most the line has actually looked like a positive line and not just from being used awhile ago. Probably nothing, but have any of you experienced this?