future tense - How to say that you have plans to go to the movies tonight?

How to say that you have plans to go to the movies tonight (but you are not sure yet, maybe you will have a pizza)? I mean there are options:

I am going to the cinema tonight.

Way too much certainty in this. For me it means that you have already bought tickets, the least.

I am going to go to the cinema tonight.

Sounds a bit awkward.

I will go to the cinema tonight.

Sounds too formal to me.