Hi mum, I feel you on the hard sell part, it can be so uncomfortable when you just want a relaxing session. Maybe you can try looking at established spa chains or maternity-focused wellness places in malls, because they usually have more transparent pricing and less pressure to commit to packages.
If possible, I would also call and ask upfront whether they do single sessions only and how they handle package sales, just to filter out the pushy ones before you even go down.