Short cycles

The last two cycles I’ve had have been 19 day cycles. This time around I am pregnant. I looked it up and it said I would have ovulated or been fertile the first 7 days after my period. The last day of my period I was sexually active. So it’s very possible to be pregnant. I’ve taken 6 tests. 2 digital & 2 first response & 2 clear blue. All are super dark and no doubt I am pregnant. However I’d be 4 weeks & 4 days pregnant today (supposedly) & have been getting positive pregnancy tests since the 23rd. Is this possible???