Twitching in lower abdomen?

My lower left and middle abdomen has been twitching often on for almost a week. It started on a night that me and my boyfriend had sex which was also the last day of my period. I haven’t had any pain or anything like that but in relation to this twitching I have also started eating this new protein brownie thing which has roughly 22 to 24 g of protein in each one and I’ve eaten one every single day. I have an eaten protein bars until now and I’ve eaten one every day since a few days before I had sex with my boyfriend. So almost 8 days ago I started eating them.  I have a feeling like some kind of digestion issue because protein is very slow digestive process and it usually happens about 2 to 3 hours after I eat one. I know it’s not pregnancy or at least I’m 99.999% sure that it’s not because I had a full period before all this started so it would be extremely extremely early for it to happen the day after he and I had sex. I am on birth control and we wear a condom and he pulls out. can anyone relate?