Is this unprofessional?

I work at a company where policy is that cashiers can only work a minimum of 15 hours a week, which really sucks since I’m pregnant and trying to save money, and none of my checks have been over 200$. Most of my shifts are 5:30-9:30pm, which is a 4 hour shift. However I don’t actually get to work 4 hours, because even though the schedule says 9:30, we close at 9 and are usually done closing by 9:05, so we clock out around 9:10. That’s a 3 hour 40 minute shift, and I only get 2 or 3 of those shifts per week.

So this week I was schedule to work Monday and Wednesday 5:30-9:30, and Saturday (today) 8:30-1:30. Notice 8:30-1:30 is a 5 hour shift which I was excited for, since it’s not closing shift I’d actually get 5 hours and not some BS 4 hours and 40 minutes.

Well I went to bed around 9pm last night, woke up at 1:30am due to insane heartburn (thanks to my very hairy babygirl at 33 weeks along) and I checked my phone and had a text from my boss at 10:30pm that said “Hey, you don’t have to work tomorrow morning, someone else wants to work the shift.” I’m thinking, uh, what? You really forfeited my hours without asking me? I feel like she should’ve asked me first if I was willing to let this person work my shift, or asked if I was willing to switch shifts with this person. It’s not like this was a shift I was covering for someone else, this is a shift I’ve been scheduled to work since this weeks schedule was made TWO WEEKS AGO.

Maybe I’m wrong, but I really feel like you’re supposed to check with somebody before you give someone else their hours because someone else “wants” them. I understand she is the boss and ultimately it’s her choice but I feel like it’s really unprofessional. I texted her saying “oh okay. Can this person switch me the shift for one of theirs so I’m not losing hours?” And she hasn’t replied, but I know she’s awake because she was scheduled to work this mornings shift with me at 8:30. It’s 10:30am and still no reply.

I’m really frustrated about this, especially because my boss knows I’m pregnant and scrapping for any and all hours I can get, and she didn’t even ask if I was okay with another person working my shift, she just gave the hours away.

But I can’t help but think maybe I’m being overly sensitive and this isn’t as big of a deal as I think it is. What do you guys think? I’m posting this in controversy because I told my aunt about it and she doesn’t think it’s a big deal, so I thought maybe several people would have different opinions.