What happens if you’re in AIT and get pregnant over HBL and you don’t want you military career to be over with?

Depends on how long your AIT is and if you can complete it. But if you're separated for pregnancy you can always return after having the baby

The only way you can get chaptered from the Army due to pregnancy is if you fail to maintain an effective family care plan. There a lot of single parents in the Army. The issue is that you can't let parents take you away from your duties. If you are in the National Guard and fail to attend your IDT weekends because you can't find care for your child then you might face that possibility. Regardless of the occupation you will need to plan accordingly. It can be challenging but you can still have a successful career in the Army and be a single parent.

Just work with medical and your Chain of Command to verify your current options. Sometimes the specifics dictate what choices are there to make. There is a discharge route for Pregnant Service Members but re-entry is never a guarantee because of service requirements, mental/physical health requirements and ever changing policies that may impact prior service folks coming back. Just make sure you know all the facts before you make any choices.