Needing some advise, can anyone help me?

Iam 22 weeks pregnant with my second child (I did not experience this pain with my first child who is now 21 months old) I went to my ob-gyn and he dismissed it as the baby growing, I was still having sever pain, when I went up stairs, moved my left leg in any direction, trouble sleeping at night, stepped over anything, and having uncomfortable popping or clicking sound when I moved a certain way in my pubic bone. I went online looking for answers and I found Symphysis Pubis Dysfunction. The symptoms were exactly what I have been experiencing. I am afraid if I tell my Obgyn that all he will say is I am wrong or something like that, I am just looking for answer in getting some relief. I feel like I am neglecting my 21 month old daughter and doing the things she loves, like going outside and to the park, but these activities make me hurt worse, what should I do?