I'm 25 not looking to conceive currently. I am on the pill, and my boyfriend also makes sure to be careful with condoms! We had sex on 25th August and I got a withdrawal bleed on the 10th September. However it was lighter and shorter than usual and it was the first time I had put two pill packs together but it panicked me at the thought of pregnancy! I've taken several pregnancy tests 19-21 days post intercourse and had a blood test at 20 days post all of which say negative!. Is it possible to have a HCG <7 at 20 days after intercourse AND a short withdrawal and still be pregnant? Can I trust all the clearblue negatives? I know the chances are minimal but the constant fear is real!