Bleeding after positive test?

Hello I had a positive pregnancy test 1-2weeks on Monday , on the clear blue leaflet it said my pregnancy willl be dated 3-4weeks

. I’ve had some bleeding today like pinky brown and some pain at my left side , Is this normal or something to worry about? The pain isn’t bad enough to take any painkillers but I’m really nervous now!!

I know it could be “implantation bleeding” but if I’ve already had my positive test and things I feel it’s too late for it? Please if you can help xx