This is my second baby/pregnancy... But never felt this with my first.

I'm feeling a knot sensation occasionally roughly were I normal find this baby heart beat. Is that the baby moving? I'm 10w1d and don't think it is? . My 12 month old I barely felt move as I had anterior placenta and felt him mainly in a few certain spots even when he was full term.

Or any suggestions what the sensation could be or the cause of it?