I'm going to say no homo
That seems odd, but why do you need to say that?
I have been saying it to myself so that I won't be disappointed if my friend is not into be and his sexual preference is not aligned with me.
It does feel awful to be disappointed but  you shouldn't say things that could make others feel bad like no homo. It would upset others and make them think you are homophobic.
I guess, but I just want to make sure I'm not experiencing feelings for my friend that I'm not supposed to.
Well, it can be complicated with the feelings you are developing with your friend, but if you really think you have feelings for him then you should try if he feels the same way. If he's really your friend then he would just accept it and not make a big deal of it, but you may also be surprised that he may also be feeling the same way about you, so I suggest you try.