How to know before ultrasound if pregnancy is Ectopic?

Question

Any signs? Has anyone had that happen to them before?

Answer

They’re usually very painful but not always. My best friend had one she was in a lot of pain.

Answer

There is no way to know for sure without an ultrasound.
There are certain factors that can make doctors suspicious of ectopic (pain, bleeding, hCG not rising as fast as for intrauterine pregnancies)...but at the end of the day, none of those symptoms diagnoses an ectopic. Those symptoms can all be from other things too (round ligament stretching, subchorionic hemorrhage, lower hCG levels from molar pregnancy, etc). 
An ultrasound is the only way to diagnose an ectopic.

Answer

Nothing in your uterus. Spotting or bleeding early on. Pain in your stomach/side that only gets worse. My pain eventually went into my chest & shoulders & by that time I was being hospitalized. I was bleeding in my diaphragm. I didn't lose my tube bc the pregnancy passed on it's own but I did need the methotrexate shot while in the hospital. I was admitted for 2 days due to complications. I'm now 28 weeks.

Answer

Doubling in pain that won't let up, bleeding if it ruptures..ultrasound is needed to confirm.