Could i be pregnant?

I have been taking the combined pill microgynon for 3 months now and i have never missed a pill, but A few times i have took my pill an hour late. I am now on my 4th day into my 7 day break and no period so i am a little worried. For the past 2 7 day breaks i have had a period like normal 3-4 days into the 7 days, but this month i am getting all the usual symptoms like cramping but only brown discharge? Could i be pregnant? Me and my boyfriend have sex nearly everday and never use a condom because i thought i was safe using only the pill for contraception. But now i am worried because i have read online that brown discharge is a early sign of pregnancy. Please help! Thankyou x