First timer, need helping deciding on a cup and determining cervix type

Hi! I'm in my early-twenties, virgin, never used tampons. I'm not sure whether I have a low cervix or a dangling cervix. Actually I'm not too clear on what the difference is, and how it affects your choice of cup. 

Is it low cervix = low cervix + short vagina canal, and dangling cervix = low cervix + long vaginal canal? If so, does this mean that if you have a dangling cervix, you need to buy a shorter cup so that it sits below the cervix without the cervix dangling inside the cup, or will your muscles pull the cup up in further along the canal and cause your cervix to sit inside even with a short cup, so you need to buy a longer one with more capacity? 

I don't have the opportunity to buy different cups and go through trial and error, so I'm hoping to get some advice here. I'm trying to decide between the Lily Cup and the Lily Cup Compact. I'm leaning towards the Lily Cup because some reviews have said it's easier to insert than the Compact version, and because of its higher capacity. Also because it's rimless. 

Originally I thought I had a low cervix so I'd have to get the Compact, but now I'm not sure. When not on my period, I have a medium/high cervix (whole finger fits and just reaches the cervix (~65mm)). On (the first day of) my period, it's like this: 

Touch cervix – Before 2nd knuckle (~38mm? Halfway between 1st and 2nd knuckle) 

Right of cervix (on my right hand side) – Whole finger (~65m) More roomy 

Behind cervix (ie towards the back of my body) – Around/Just past 2nd knuckle (~40/45mm)

Left of cervix – Past 2nd knuckle. Less space, tighter fit (~45/50mm)

Front of cervix  – Halfway between 1st and 2nd knuckle 

(Everything might be lower/shorter during the later days of my period)

Does the fact that I can reach further around the sides of (though not to the front of) my cervix mean it's dangling? That I have less space on the left hand side makes me think it might be tilted too, is that right? Does it being tilted mean I have something else to consider when using the cup?

What length cup should I get? Bryony Farmer of Precious Stars Pads has mentioned being able to use the Lily Cup comfortably (without the stem) even with a low cervix, which makes me think I'd be fine with that one too. Would you agree, or should I go with the Compact to be on the safe side?