Large cervix??

I use the diva cup, but it would sometimes leak even though I know I put it in right. 😑😑 I told my gynecologist and he suggested the size 2 (even though I’m 21 and have never had a baby). It works perfectly! 🎉 He explained the cervix wasn’t completely covered by the size 1. Any more explanations on what a large cervix means, how would that affect delivery one day, does it really make a difference in anything at all? I’m just curious now!! 😯 Not worried, just interested!