When to start aspirin?

Michelle 🇬🇧

I’m ttc right now and taking folic acid daily and vitamins. Thing is my last pregnancy I took baby aspirin 75 as I’d had a still born at 25 wks due to placenta and blood flow issues. So I was told to take it with my last. I don’t remember when I started though. Do I need to see a doctor or just buy some? When the doctor told me to use it last time I just bought my own from the pharmacy which they said was perfectly fine. I forgot when I started though 😬 does anyone take it? How many wks pregnant where you when you started? Thank you x