help! withdrawal bleed or period???

I was on the pill, stopped to have my monthly break (ended up being for 10 days, 7 of these I had my withdrawal bleed). I then had 1 pill, but then we decided we would TTC. 3 days after having the 1 pill from my new pack I have started bleeding again... is this another withdrawal bleed after 9nly 1 pill or is this an actual period returning???