Clothes not fitting !

I'm 11 weeks and cannot fit in my jeans! Isn't that early?? I've only gained 2 lbs. Anyways... so for sometime I've only been wearing leggings... now if it was warmer outside I could wear my Maxi Dresses and skirts. But it's not... it's January and it's still cold. Any suggestions on where I can get some affordable maternity pants/clothes?

I've looked at ross... horrible selection. I checked the Old Navy next to my place.. super small and not that good of a selection...maybe different locations vary? Any help would be nice. Thanks !