Well, well, it should always be a woman's choice whether to give birth to a baby or abort it.
But if we talk about fetal development, research says that the higher structures of the brain that are necessary for consciousness, that are necessary to feel and sense anything start developing between 12 to 16th weeks, that is 3 to 4 months. So if a woman wants to abort this period is the best time, before 3 months, as the embryo doesn't have any consciousness, it doesn't feel any pain and it will be less invasive and the chances of health risks for the woman will be comparatively less.
After the 16th week, brain development continues till and around the 22nd week. It is only after this development the fetus will be able to sense and feel things around it. So between 4 months to a little over 5 months, abortion is ok as the embryo is still developing it doesn't have a sense of self. But abortion in this period can be invasive and is comparatively not healthy but still ok. Nothing wrong if a woman wants to opt for abortion before these 5 months. 5 months are more than sufficient to make a decision.
After these 5 months, a little over 2 or 3 weeks, the embryo will be fully formed and developed. It starts feeling what you feel, you are happy it is happy, you are sad it is sad. It is still a part of you but it got its own brain now. It just sits there rest of 3 or 4 months in the womb just to gain healthy weight. That is why premature deliveries after 6 months survive if given enough care. So after five months if a woman opts for abortion, in some countries it is mandated by the law to give anaesthesia to the fetus before doing an abortion. It will be invasive, it comes with health risks, and some women end up not conceiving again in the future.
So if a woman is opting for abortion after these 5 months, she must have some very strong reason. You had enough time to make a decision, you didn't use it, it is your fault. So if you don't have a good enough reason, well, you will know what to do if you are not a terrible human being. It is always your choice, so choose wisely.