Hi Hollywood,
Every woman is different and every sign means something different to different people...
You are 16 weeks along so that is reassuring... as most people miscarry in the first trimester.
Often pains in the back/side can be from your uterus stretching to accommodate the growing bub... sometimes they can feel like period pain.
If you are miscarrying you will often have a combination of pain (cramps), bleeding (usually fresh blood but not necessarily a lot of it) and loss of pregnancy signs (no more sore boobs, no more constipation, no more acne).
It is really important that you see your doctor of go to the local ED as it isnt healthy for you or your bub if you are worrying. I know this is easier said than done.
When was your last beta hCG level done? Often your doctor can repeat it to see if it is doubling every couple of days.. Also are you having antenatal care anywhere yet because if you call them you can often get in to have an ultrasound to check everything is ok. Dont be scared to go to the ED at the hospital - that is what they are there for.

I hope you have a support person that can be with you while you are stressing. Please try not to worry as i wonder if that is why i lost my baby - too much stress... i regret it now.

I'm thinking positive thoughts for you. Please call someone TODAY - GP/Emergency Department/Antenatal Clinic.

Emily