It feels like a strong clench that lasts a few seconds. It's usually somewhat pleasurable, though it's sometimes uncomfortable because I cannot release the muscles.
Has anyone ever experienced anything like this? Is it normal? (It's not painful and doesn't bother me, but my Google searches have only returned vaginismus-related things and I'm concerned that this could be a sign of something that might impede future PIV experiences.)
(Also, it might be relevant to note: these contractions are different than those I experience during orgasm. They are stronger, last longer, and feel different. I usually have one or two of these contractions at a time; during orgasm, there are many more contractions that happen at a quicker pace.)