Who is right in this situation? (family argument)?

Alright, so I have swim practice on Tues and Thurs.

Today just now my brother told my mom that I was going to swim practice... and my mom flipped and asked why. I said you said I could a week ago (which she did...I recall it), and she said no, why do you wanna go?

I said because I want to swim...and she backfired with "you could swim at your uncles house" (we're going to CT on Thurs then to Penn). I told her the pool was circular so I couldn't actually "swim".

Then she said I couldn't cause the time wasn't right; then I asked whyd you tell me I could last week then? And she said she wasn't thinking straight that time and she cursed and flipped out on me...

Who's right? She told me I could go, and I asked her 5 times to make sure. (Last week<<)

But, the time really doesnt fit, but I told her that she told me I could and she kept yelling and screaming at me calling me weird and telling me that I wasn't flexible....

After she said I couldn't go I was like okay I won't go, but she still kept arguing....