Am I using fractional time signatures or am I just misunderstanding?

I am not very knowledgeable about music theory but I believe I have written a part of a song that is alternating measures of 6/8 then (3&1/2)/8

The only way it makes sense being counted is (1, 2, 3, 4, 5, 6) then (1,2,3, and) then (1, 2, 3, 4, 5, 6)…

It is like the last beat of the second measure is quicker than the other beats. Counting it as three beats does not quite work and neither does 4. Am I misunderstanding something very basic or is this a fractional time signature?