Am I in the wrong?

My mother in law booked a cruise for my husband and I to share a balcony room on carnival pride with her, us two, and my father in law (which I heard was the smallest ship and rooms) in May to cut costs. I am grateful yes, but circumstances are different this trip. We offered to pay for our own room. I get my period that time. I have endometriosis and my periods are excruciating. I feel sick, etc. I am comforted by my husband, heating pads, warm showers, dark rooms, etc. bottom line, it’s a time where I don’t want to be around anyone. I’d like to be able to go back to our own room, and be able to do what I need to do in privacy. This is why I am leaning towards us booking our own room. I texted her about it and she’s coming over to talk about it.

I should not have to explain myself to anyone. I don’t think it’s wrong for me to want our own room for that just reason. I don’t think it seems “ungrateful.”

Am I in the wrong?

At the end of the day none of them but me will ever understand how I feel during that time of cycle.