scared... anyone else every go through anything like this?

Those of you who have had an ectopic pregnancy can you share your experience? I went to the ER on Sunday night with abdominal pain. It felt like gas cramps. The pain did go away within a few hours. They did an ultrasound and they found a cystic lesion on my left ovary and free floating fluid. I haven't had anymore pain since then. My hcg was 113 Sunday. They sent me home and I followed up with my OB today and they did some betas to make sure my levels are doubling like they should. Thursday they're seeing me again for more blood work and an ultrasound. Has anyone ever had a similar experience or had an ectopic and can explain what you felt?