You said you had the withdrawal bleed? That is your period. You don't get a "real" period with the pill--it's only withdrawal bleeding. Sometimes it's very light because of the pill. Also, your pill break is supposed to be 8 days or did you stop before you'd finished the pack?
Start a new pack and continue on. Since you did bleed, I don't think you're pregnant.
Sniffles and a sore throat are not a symptoms of pregnancy. You may be sick and that may throw things off and make you feel bloated and tired. Take it easy for a couple of days and if you don't feel better, go see your doctor or pharmacist (I'm assuming you're from the U.K?)
Also, you titled your post "wishful thinking"? Do you want to be pregnant? If you do, why are you on the pill?