Plusing sensation in abdomen

In the past 2 weeks I noticed a strong pulse on my abdomen, I also noticed that it is localized to the left side of my belly button and only notice this when laying on my back. I only notice this heavy pulse when I press into my stomach - when I do that, I can feel the beating. It is very strong and today I noticed a small bulge on that side too (about 1 inch or so) again localized on the left side of my belly button - slightly lower. Could this be pregnancy related? Does anyone have similar problems or any advice to offer? Other symptoms I have: back pain on tailbone, a full-sensation in my stomach, no appetite., throbbing beating. I talked to my obgyn he said not to worry but I found that it could be an abdominal arotic aneurysm but he said its mostly not they won't run test cause the baby is in the way, I had a sister pass away right after birth because of an embolism don't know any details I was very young then. Was wondering if this could be the same. has anyone had similar experience what did y'all find out?