TTC at 33

Pam
Any suggestions on how to initiate sex without it being awkard. Been together 16 years and it was never an issue until maybe 2 years ago. He doesn't initiate like he used to, and I've never had to, so I feel like it's Unatural for me to say ok time for sex. Even when I tell him ok this is "the week" we need to try we average twice a week, very frustrating. Been trying to get in sync for four months, any suggestions?