Cervix Scratch/Tickle??

As of Friday I am 28 weeks along and I just started experiencing something new (yay!). Starting a few days ago, and increasing in frequency today, I am experiencing these weird little twinges down south. Basically it feels like something is scratching or tickling my cervix/pubic wall. On top of it I have a pretty intense but dull pain in my lower back, just to the right of my tailbone and it shoots down my leg (I’m guessing this is the wonderful work of the sciatic nerve?). Has anyone experienced these weird sensations during their pregnancy? They only last a few seconds but it’s such an odd feeling it’s hard to hide it when it happens. Sometimes it even feels like I’m going to pee myself afterwards but I haven’t yet!🤞🏼🤞🏼🤞🏼