chemical pregnancy?

So I've had four test with faint lines, they've been getting increasingly darker over the past few days. And now the day my period is supposed to show up, it started out light but I can tell it's going to get increasingly heavier. Is this a chemical pregnancy? I don't know why I do this to myself but I already got my hopes up, and I've already had a miscarriage before. I'm just really sad and feeling like I'm never going to be a mom. I nannying for a living and it's becoming kind of agonizing taking care of a baby and not being able to have my own. Anybody with anything positive to say would be appreciated!