I ended up in maternity jeans about 5 weeks in. It was partially due to bloat, partially that I couldn't stand having anything pressing on my stomach.
I tried the elastic-button loop trick, and I do use it on my dirty painting jeans, but it doesn't work with my work pants because then my zipper stays down, and my shirts don't necessarily fall that low.
I also bought a belly band. Unfortunately, I've got a very strong hourglass shape, so my waist is much smaller than my hips. (Even now, as my waist is thickening up, it's still much smaller.) Because of this, I had to pull the belly band so that it was down and kind of tucked under my buttocks. If I didn't, it would roll right up to my waist and settle there. Every time I stood up, I had to tug it back down. I only wore it once, and then accepted my maternity pants fate.
I wouldn't recommend it yet though because early on it is just bloat. At first I tried the old rubber band through the button hole trick and that worked a little bit my pants were still digging into me, but after I got my maternity jeans (which DO feel so much better than the other ones did, won't lie, just expensive) I found out about the "Bella Band" which is just a band you wear around your belly and top of your jeans and allows you to keep your jeans unzipped and unbuttoned but you can still wear all your existing jeans. Although on the other hand, I'm really glad I do have my maternity jeans, because they're expandable and I will have them as I continue to grow, and they are some of the only pants I'm able to wear now! It's those pants or leggings, and not all leggings I can wear anymore lol. Maybe I should invest in the bella band; it's not too late!
they're not bad! Pretty much exactly the same as my £19 ones from new look x
