google calendar won't display

I just got an iphone 5s with ios 8.1.3 and am trying to get my google calendar linked to the calendar app on the iphone. I have added my gmail account and made sure that "calendars" is on, but when I go to the calendar app none of my google calendars show up. I only have this problem with gmail; the calendars I have with my other accounts (icloud, hotmail, outlook, etc.) all display and I can show or hide them (by using the checkboxes) on the calendar app but I don't even see a "gmail" heading in the calendar app and none of my gmail calendars display at all. I've tried selecting secondary calendars (which are all properly selected) from here (https://m.google.com/sync/), I've tried deleting my gmail account and adding it back, I've tried turning off my gmail calendar and turning it back on from Settings (with and without turning off my phone in between), but nothing has worked. Is there anything else I should try?