Ok..whenever I masturbate and enter my fingers or my boyfriend fingers me we hit this weird thing in my crotch. I don't think it's my cervix(sp?) although I don't know how far in the cervix is. We hit somthing about three inches in. It's like a little wall or somthing. I guess it like hangs down, almost like a ball or something there. I don't know what it is and I don't have a very good mental picture of inside me. I was told it was normal and all women have it by my gyno, I just don't know what it is. I don't know how to maneuver around it either. Like, I can maneuver around it but I guess once I have sex, since my babe's dick is much bigger than a finger the dick will push it up or move around it.
SOMEONE PLEASE TELL ME WHAT IT IS! 
thank you. So when aroused I'm guessing cervix is different? Also when having sex does the penis move into the cervix too? Or does it just hit the cervix?
no i doesn't go inside it
it can bump into it but that usually doesn't feel too good
i think it moves out of the way.
some positions like doggystyle allow for deep penetration and sometimes those can feel uncomfortable.
you just have to try ones that feel good.
here is a link to female anatomy diagrams
yes i would guess its the cervix
a woman's vagina is only like 3-4 inches deep i think
how close your cervix is to the opening of your vagina sometimes depends on what position you are in.
like if you are sitting up then it won't be that far away.
i guess sexual positions to try would be you lying down and those to avoid would be you on top sitting straight up and doggystyle usually gives me some discomfort too.
don't worry tho, the vagina accomodates things much larger in size, so eventually you won't have any trouble.
also when you are aroused things move around in there...read that page i linked it mentions it.
just remember to take things slow.