Pill and pregnant, how do you notice it?

Hi, a question!

I forgot one pill in week 1 or 2 (don't remember exactly) and took it after about 24 hours.
Now I got my period on Saturday, but since then I've maybe had 4 pads with some drops of red, pink and brown blood..
1 time when wiping, dark brown and a bit more.
So it's very light and I'm having quite a lot of symptoms.
I read online that if your withdrawal bleed is light and you have symptoms, you could be pregnant.
I'm going to test anyway but just wanted to ask!
Anyone has experience with this?