Chances of pregnancy while breastfeeding?

My son is 8.5 months old, breastfeeds day and night as well as eats 3 meals of solids a day + snacks.

I have not yet had a period since giving birth.

2 weeks ago my hubby and I had sex and he finished inside, since yesterday I’ve been feeling fatigued, have a bad headache and feel a little sick to the stomach.

I know there’s always a chance of being pregnant.

But do you really think I could be pregnant without even having a period yet? 🤔🤔

I want to pee on a stick but also freaking out because I’m not ready for baby number 2 and I should have known better than to have unprotected sex 😅 but in the moment we took the risk