I am not pregnant and yet since last night I have had vibrations in my lower abdomen on the left. They last 4 seconds and start again every 20 seconds.

Hello,

it may be contractions of your uterus even if you are not pregnant. Pregnancy is not the only cause of uterine contractions. A hormonal imbalance may be the cause or something else. In any case, it will be necessary to have a thorough examination by a doctor in order to have a clear diagnosis and find a solution to your contractions if they still persist.

Have a good time!