Pink spotting

I am 4 weeks 2 days and yesterday I had some pink spotting only when I wiped. It was a little red at first then went to almost pink tinged discharge. This is my 4th pregnancy and I haven't had this before. It lasted a few hours and didn't go onto knickers just when I wiped and today it's gone. Anything to be concerned about? No cramps or anything, I have had the odd shooting pain when I was in bed