I hate to say it but... Start over. The actual dimensions of the cups you've picked out are all over the map. Do a little self-exploration and figure out what brands would fit you best. IGNORE the directions that show a cup sitting at the entrance of your vagina with a cup length or more between the rim and your cervix. That is just plain WRONG and why oh why do all the cup companies draw it that way??? In real life any cup will settle (O) around your cervix and height of the base of the cup will be relative the length of your vagina and the length of the body of the cup. You want the base to be just above your pelvic floor muscles. (Insert your finger, give it a little squeeze. That's them. Cups sit above them.)

If a cup is too long, it will press on your pelvic floor and shift off target or poke through, feeling like it wants to escape. If a cup is too short, you'll have a heckuva time reaching it for removal.

Also consider capacity to match your flow and both shape and stiffness for comfort. Softer is often more comfortable once it's in but stiffer pops open more easily and some say seals more securely. Compare side by side photos. Pointy or blunt base, flared rim or not, stout body or slim. There is a lot to consider but also trust your gut feeling. It's probably right.