gaining weight??

Ma
So I'm pregnant with my 2nd my youngest is 7 months When I was pregnant with her I didn't start wearing maternity clothes until I was 6 months! This one though I feel like I'm gaining weight super quick or bloating worse than my other pregnancy because I know it can't be the baby most definitely because I'm only 5 weeks. I work out everyday and eat healthy but my pants are getting harder to button. This makes me worried that I'm gonna look pregnant sooner than my 1st cause we really wanna wait to tell people cause I'm just paranoid like that, but has this happened to anyone?