Yup... there definitely are days where, for whatever reason, I don't care too much. Sometimes they last for a few days.
But then, without fail, the dysphoria will come right back and kick me in the butt, and I'll be right back to feeling like crap because I'm not a girl yet.
The key is, though, on my bad days, I still don't want to go back to being a guy. It's just more of a "I'm not as annoyed as usual that I'm not a girl yet" kind of feeling, where I feel like I don't care for a while.
Don't worry about doubts. They're healthy to have. They make you think. Ask yourself why you're having them. Is it because you're tired? Is it because your brain was so overloaded with dysphoria that it couldn't keep the desires up, and thus needs a break? Or is it genuinely because you want to stay a guy? Let them happen. Think about them. Work them out.