Could I be pregnant on birth control patch?

Hi, I've been using the contraceptive patch for about 4 years... Me and my boyfriend have decided to try for another baby. So this month my patch has been on and off.... I was away on holiday on the day I was meant to change my patch on Friday 9th August (week 3) but I forgot to bring a patch with me... so I had a little withdrawal bleeding so I ended up putting back on, on Monday 12th August... I then took it off again on Friday 16th Aug and It's now Sunday and I haven't had any bleeding. I've also had unprotected sex with my boyfriend a couple of times. While it was off.... Could I be pregnant?, I did take a cheap pregnancy test yesterday but I didn't do it on my first morning wee, the result was negative.... but still no bleeding..