Twins 6w one gestational sac irregular

i. This is my third (and unexpected) pregnancy. I have a one year old and a two year old, then found out last week I’m pregnant again!!! THEN found out at an early scan that I’m expecting twins!

However my worry is one of the twins gestational sacs is irregular. This was reported on my notes and the epu nurse said it can mean the sac is collapsing. I felt like I’d had such magical news and then it was snatched away. I’ve been googling like crazy and most posts about irregular gestational sacs aren’t positive. I went for a private scan today and measure 6w and saw two heartbeats ?? however one of the sacs is an irregular shape but the sonographer didn’t seem worried at all as hb was strong. I’ll attach a photo, wondering if any other mums of non identical had similar experiences and went on to have normal pregnancies?