Have a chat with the place you have booked with and see what they can advice xx
I think they won’t, not because of the treatment doing anything. But for their liability if you do miscarry they wouldn’t want you to seek compensation from them. They might be able to offer other treatments or you may have to wait until the 2nd trimester if you want a massage.
Should be completely fine, baby is way down in your pelvis still so lying on your stomach or someone pushing on your back can’t really do anything to it at this point
I had a massage and facial booked when I was 5/6 weeks pregnant, the spa would only offer me a manicure or pedicure as an alternative and even then it was literally just nail polish, no hand massage or anything
Try switch it for a facial :)