Yep, normal. Just keep an eye on them that all they are are BH. If you think it maybe triggering prem labour I would avoid sex....( sucky I know, a friend of mine can't have sex after about 24 weeks, they just stop until she reaches 37weeks when labour is ok. And then she has all her babies at 37-38ish weeks (4 bubs) some people just have a touchy uterus )