Did it feel like a jolt? I had sciatica with my first pregnancy and I would feel a strange sensation from my lower back down my leg. The doctor said the baby was pressing on a nerve.
i had that happen n i was told it could be the baby moving or ur insides streatching, many things when ur pregnant.
i dont recomend hitting ur self again try just rubbing it, that helps make it go away faster.
i got a lot of pain around that time and i had a bunch of back pain, cramps, constipation, legs n feet swelling but the best part for me was i felt her moving a lot more inside my belly
but all pregnancys r different so u might not get any of that