trouser trouble, 17 weeks - UK based

💖💖💖
Ok people I need advice. Been looking for maternity trousers as regular ones are getting tight now and I'm struggling. Went to H&M today tried a size 12 skinny leg (as normally a 10/12 skinny) and they were like hipsters and felt like my butt was falling out lol!! Wondered if anyone had any recommendations or if you had to go for a size bigger than you were in 'normal' jeans if that makes sense?