Stabbing pains across whole mid belly 34 weeks

For a while maybe even over a month I started to get real bad sharp stabbing pains through my mid belly and goes to my back. I have gotten checked but was told it was nothing and since I’m small I could just really feel EVERYTHING.. well it’s still been going on and it just hurts bad. Like could it be constipation or gas or anything also? I have been pooping fine sometimes it can be a bit harder but a lot of times it’s been very loose.