Oo, normal yan sa 5 months, first time mom! A few of us went through the same thing, it's usually round ligament pain kasi lumalaki na ang uterus at nag-stretch ang ligaments, lalo na kapag movement like walking or lifting your leg. The good news is nauubos lang siya when you're at rest, which is a sign na hindi serious, but definitely mention it to your OB next week para peace of mind mo and they can confirm if that's what it is.