What are these sensations?

Hi All,
I was wondering if you ladies might be able to give me your opinion. I have been having some feelings/sensations which I find a bit hard to describe but was wondering if anyone else might experience the same thing and if so have any idea what it is?

I first noticed this when I fell pregnant last year (which ended in MC) and now I seem to notice it every month at different stages in my cycle. The best way I can describe it is a feeling up inside (not sure if cervix or uterus perhaps...ashamed to say don't know my body that well) like twitching or butterflies, and then a dragging sensation (which does not happen all the time). It might go on for just a minute or so, but other times lasts for 15minutes or more. Sometime it is just the twitching feeling, and other times I feel a dragging sensation afterwards.

I remember when I fell pregnant I was feeling this almost daily for a while there and it worried me alot.

I had this feeling while lying in bed this morning (6DPO) twitch twitch twitch drag.....so I thought I would pop onto BB and see if anyone can give me some advice as to what they think it might be or if anyone else has experienced something similar.