5 weeks pregnant possible tubal pregnancy

Hey ladies, I need some help advice or just some education. I found out I was pregnant and confirmed it at the hospital through bloodwork. Also I had a ultrasound but was told it may be to early to see the sac. I'm going for a internal ultrasound in the morning. However I've been having pain in my lower sides, it's both sides sometimes more the left but it is on both sides. So the doc is a little worried that's why I'm going first thing in the morning. Can someone tell me this is normal ? I'm so scared for what can happen to myself and this baby. Anything good and bad will help me. I just need information.