Hello girls, could anyone tell me if they had something like this?

Hello girls, could anyone tell me if they had something like this? Around the third trimester, the last few days I feel like my heart thumped a couple of times and then it's fine, there's nothing else besides fear, then I calm down and everything is fine, maybe someone else has experienced this? Just scared that it might be something serious, I did an ECG five days ago and everything is fine.