AITA for not going on a weekend away with my friend?

So my friend rang me yesterday saying that she has a consultation abroad and would like to make the most of it by exploring. She asked me to go with her because her mum can’t make it. The reasons I don’t want to go are: * she always gives me last minute notice - she wants to go in two weeks. when I suggest to go out she’s “busy” and it’s always meeting on her terms. * she sucks the energy out of me and can literally bang on about her problems for hrs and hrs without asking me how I am. I feel like her counsellor and not a friend. I have my problems too! * I’m in my first trimester and worry my symptoms could worsen in a couple of weeks - I’m not ready to tell her I’m pregnant and don’t want her to realise if I do end up going. She wasn’t that happy when I announced my engagement and tried to put me off getting married two days before my big day so can you imagine how she’d react to my pregnancy I made an excuse and now she’s saying it’s “typical”. I changed the subject and asked if she could go with anyone else.