How to handle boss/work situation? :(

I am currently just entering my second tri of pregnancy. The job I have was originally a PT position , as I was in university up til spring. It felt more so like full time though. It is a small business (salon type) and my boss who owns the salon has had issues with finding employees. I am one of the longest workers to last accoriding to customers . I have seen her go through several employees within days or weeks since I started in January . While I was working literally almost every day and in school I didn't mind the money.

Now it has just been her and I for awhile. Well due to my pregnancy I have been having aches and sickness etc. Called in sick twice. Last night contracted some sort of flu or mild food poisoning (person I ate out with had it as well so I know its not my usual nausea from being preggo). I texted her saying there is no way I can work in AM and she flipped !!!

I feel guilty to make her work her shift and mine since its just us two and she already has a heavy workload but with my pregnancy I cannot handle working 6 days a week. Not to mention this was a virus that could potentially be contagious. We agreed she will hire someone new but she always has so many issues finding someone and I feel trapped. If I am in bed with flu AND pregnant I feel like I sb entitled to stay in bed. She still expects me to work a shift in the afternoon than work sat all day.

I hate disappointing people but I'm reaching my limits. I can't be out of work but I can't be the only person she relies on when originally this was a part time position and after I leave I will 100% not be coming back . It is not a job I would have as a career and though I take my work serious I'm not going to be her only backup for her own company when I'm not even that invested !!!! What do I do?

Meet with employer and kindly explain, "I'd like to give you an option. I've had medical advice, and I intend to cut back on my work hours for the duration of my pregnancy. I can either work [insert desired number] hours per week for you, or I can give you my notice today in order to take a less demanding position elsewhere. I need you to consider your answer carefully, because I won't accept any hours beyond [X], and we need to manage any expectations that I do so."

It's on your employers to manage their own shop, and it's on you to impose your desired boundaries. If employer does not agree to those or operate within them, then give your notice and apply with temp agencies during your free time as you work your 2 weeks or less for current employer.