I lived with my aunt in a senior/disabled apartment as her caregiver. She died , my ex girlfriend was on the waiting list . She got my aunts apartment , So she moved into my already furnished apt, I am also listed as her caregiver . I pay half if not most of the bills. Everything in the apartment belongs to me and my aunt . My ex has only clothing and a few random things. Can she kick me out without notice ? And how can I get all my things if she changes the locks ?

If she is the leaseholder, then you are either classified as a roommate or, worse, an employee. As either you have very few rights. If classified as an employee, you can be terminated at any time. You would then have to get a court to allow you to recover your belongings. Even as a roommate, you would be considered her tenant and she can terminate that tenancy at any time depending on local laws (Note: any question on law needs to include your general locale as laws vary by area.). '

I would strongly suggest that you put together a video of all your belongings with proof of ownership. Then store that video and proofs off premises (i.e. a safe deposit box).

She may not change the locks. If she does, you can have to police go with you there to tell her so, and let you in.
But you can't sit around a minute longer. At the least, hire a mover and put everything of yours in storage.
CARRY with you at all times paperwork regarding your aunt's death, some utility bills, etc., to prove your status to enough extent for the police.
Some of this depends on when your aunt died, and how her estate (possessions, money, etc) was handled.
If she had no money and there was no probate, and her furnishings were all she had, then it seems reasonable that unless other relatives want to claim them as her closer kin under state law, they are yours.
You are in a bit of a gray area though. Your ex might try to claim that you are now trespassing, that you should have been out by a certain date. You don't give us any of that timeline.

As I read this, OP's aunt was the tenant. Then, when the aunt died, OP's ex moved in and declared (as had the aunt) OP as the ex's caregiver. Thus OP appears to have been employed by the ex as a caregiver. Now the ex is kicking the OP out.

If this is the situation, and OP was never a tenant (as far as the landlord is concerned, but instead always an employee of the tenants) the landlord is within his or her rights to have the ex change the locks (in behalf of the landlord).

OP should ask the police if they will assist her to recover her things. If they refuse, OP will need to get a court order.

AK lawyer, the ex was on the waiting list to get the senior/disabled apartment, and got it after the aunt died.

[edit - I agree the rest of you are right]

I agree with AK here. The OP appears to be an employee of the tenant of the unit. Previously it was the OP's aunt and now its her ex girlfriend. So the OP appears to be an employee. Which would mean she doesn't have the rights of a tenant. Which means she could be locked out.