Maybe he's just not that into me anymore.

I've been trying to do some research on how often married couples have sex. It's a little difficult because everyone has different circumstances. Each blog I read has the same info and the same generic advice. The truth about my sex life is that it doesn't happen nearly as often as I would like. We have sex maaaaaybe 3 times a month. Which is not only super frustrating, but it's also adding to our issues TTC. We only have sex one during my fertile time. I don't know what the problem is tho. It's certainly not for the lack of opportunity. We currently live alone and we have no children. We have no excuse. We've been together for 12 years and the first few years we had sex all the time and it was spontaneous. We tried all kinds of things and now it's "vanilla."  It's planned ahead of time. It only ever happens at night. In the bedroom and only after we both just showered. Separately. The struggle I really have with it is that I can't tell anymore if he just has a low sex drive period or if he's just not attracted to me anymore ... I know he loves me. That's never been a question to me. He just doesn't feel like he's my husband. He feels like a roommate. Maybe he's just not that into me.