Mine were the worst in weeks 11 and 12 - I don't know if it's too early to get round ligament pain, but from what I read, that's what mine sounds like.
Don't worry - your uterus is growing and moving up - this is a major growth stage. I've also had a bit of brown discharge as a result. Everything is fine! Saw the baby a couple days ago at my 12 week scan and everything was perfect.