Measuring behind

So I posted a few days ago stating they couldn’t find a sack or anything when they did an ultrasound ! Well when I went back a couple days later they were able to now find a sack but instead of measuring 7 weeks I was measuring 5 ! My progesterone and hcg levels have continued to rise as well ! They scheduled me for another ultrasound in a week and a half ! Any other mommas have any positive results from an ultrasound like this being behind ?

I should also state my cycles are very irregular and even my obgyn stated. My cycles are all over the place and I could’ve very likely ovulated and implanted late .