3D/4D scan

I had a 3D scan a few days ago, and the woman couldn't get a picture as she said his face was buried in the placenta, even though I've got posterior placenta?  and then had his hand and foot in the way. They've given me a rescan date.. But I'm just worried it's due to my size? I'm 247lbs, 5'5'' tall, and carry a lot of my weight on my belly. My 29 weeks pregnant.. Pre pregnancy clothes size was UK 24, and now 18/20! weight was over 300lbs! Losing that much weight have me the confidence to book a 3D scan, but now feeling gutted! Anyone else similar size as me had a successful scan? Just makes me not want to bother going for the re-scan!