Shaking / going numb while sex

So during the first night my boyfriend and I had sex like 6 times, it was also the night I lost my virginity. Anyways, the first time my legs started shaking and i couldn’t really move them, it felt like I went numb. It didn’t hurt so i told him just keep going and I we did.

Not that long ago maybe like 4-5 weeks ago him and I did it in the woods and he bent me over on the four wheeler, anyways my legs and arms started to go numb like they did the first time.

Has this happened to anyone else ?? Or anything similar happened ??