Pants fit different at 7 weeks

So this is my 5th pregnancy. I only have one living child who is 15. Miscarriage this time last year. I am currently 7 weeks. Had an ultrasound yesterday after a bleeding scare Sunday. Baby measured 7 weeks 1 day and heartbeat 148. I’m just curious is anyone else having the issue of pants fitting different? My fiancé says there’s no way this early that they are fitting different, but I haven’t changed the way I eat so I’m completely confused. I do feel very bloated most of the time. Lol