I want to ask my girlfriend a couple questions to see if she loves me do you have any in mind?

My girlfriend said she doesn't know if she feels the way she used to about me and we have been going out for 16 months. I really hope it isn't true but, I think it is just a phase. Every relationship goes through a time of doubt am i not right? So what are some questions i could ask her to show me her subconscious thoughts about me. If she truly loves me her subconscious will give it away so please someone help.