How to deal with the guilt of saying no to things when pregnant

Hello all!

Just wondering if anyone has any tips/thoughts on saying no to some social events/parties/commitments etc. whilst pregnant...specifically the guilt of disappointing people when you just don’t feel up to attending/doing something?

I’m finding myself having to say no to more as my twin pregnancy progresses and becomes more tiring, pregnancy symptoms play up etc. but I’m not quite at the stage where I feel ready to tell everyone I’m pregnant yet (things could still go wrong at this early stage)...some people seem ok with me not being able to do things because ‘I have other stuff on’ but others are notably disappointed when I fall short of their expectations. That makes me feel awful, I hate disappointing people, and I also feel a bit stuck in this instance as I don’t feel able to say specifically why yet!

It’s an awkward stage, I suppose, and I just wondered how other people might be managing it? I really don’t like feeling this way :(

Thank you ever so much in advance for any input!