Can Ncos require pregnant soldiers to participate in monthly ASU/AGSU inspections?

SPC Grant, the question you pose is quite common. BLUF: Give your NCOs and chain of command an opportunity to learn from this, as you will learn from it too as a future NCO.

On 19 April 2022, the Secretary of the Army signed Army Directive 2022-06, which provided updates to parenthood policies. Regarding uniforms, this AD states that "Commanders and supervisors will not require Soldiers to wear ASUs/AGSUs while pregnant and 365 days postpartum." See para 4.c.2.a.

EDIT ADD: Having your uniform inspected is NOT against this AD. If you have to WEAR the uniform for inspection and you are pregnant or postpartum <= 365 days, then yes, it violates this AD.

Some younger commanders and NCOs may not have a lot of experience yet with policies pertaining to parenthood, pregnancy, and postpartum. My recommendation: show your NCO/supervisor the AD and the para. The AD makes it very clear. That should be the end of it. If not, ask your commander/1SG/CSM to please check with the Inspector General (IG) to ensure the AD is being followed appropriately. You could always go to the IG yourself, but I think that being a member of a team also means that you should give your chain of command an opportunity first. I hope this makes sense.
https://armypubs.army.mil/epubs/DR_pubs/DR_a/ARN35255-ARMY_DIR_2022-06-000-WEB-1.pdf

Yes, you may be required to participate in monthly ASU/AGSU. However, that does not mean you have to wear the uniform. Direct them to the regulation/directive that precludes you from wearing a uniform. If you want to protect yourself from further abuse dig into the regulations. Learn them inside and out. Keep up to date on all updates. It will help you though out your career. A couple of months ago I had to communicate with Army G1 on an issue with DFAS refusing to pay DLA twice in one year. They paid it but not until I showed them in the JTR where they were wrong. It took three months but they paid up.
BTW, try to use a little tact when addressing the issue with your command.

As COL (Join to see) and COL Dan Ruder alluded, you can still participate without wearing the uniform. We used to call the a "hanger inspection." You still bring you complete class ASU/AGSU, properly pressed, with footwear properly shined and appropriately headgear. ASU/AGSU jacket should be set up completely, according to regs. All awards, badges, name plate, unit awards, rank, etc. Then when everyone else is in their dress uniform, you are in your maternity ACUs, and holding your uniform, on hanger. If you are too deep in pregnancy for extended standing g, you sit to the side, with your uniform laid out on a table.

We used to have ASU inspection every month. Invariably, there would be one or two people who could not do it IN uniform, because of training or pregnancy or whatever. But they would still have it on a hanger. It should not be a completely unknown phenomenon.