Irregular periods, positive pregnancy

Without running right to my doctors office this holiday week... what’s your best advice on how to gauge when I “missed a period” or cycle day or something to see how far along I could possibly be...? I didn’t have a normal cycle the last two months, so I really don’t know when I ovulated or should be missing my period. I know the doctors office will ask when my last one is and probably do an internal scan to see if they can measure anything

, but I don’t wanna rush to them just yet... I’ve never gotten such strong lines before, and the last time I tested was Christmas eve (morning) and that test was negative. The First Response pictured was yesterday morning (line shoes right up) and the One Step I just took 5 minutes ago...