In need of help.

Okay so me and my partner have been trying for some time now.  I usually have irregular periods but for the past two months they came on the same day the 19th so does that mean there back to regular this month we tried again on all the right days and I've been taking prenatal vitamins and getting my body together. We'll today is the 19th and my period didn't come I don't kno wether I shall test or wait. Really don't want to get them negative results so I want get my hopes up. Help please could I be pregnant ?