alesse and it problems

Has anyone gotten pregnant on alesse by using it correctly and not having their period regulated ( with spotting and all)? I'm on it since august and till now my period is irregular.... my concern is will it still protect me against pregnancy ? Since the pamphlet says to be protected the estrogen must be 20mcg and more which in this case I'm taking 20mcg! Please let me know I was fingered by my boy but not sure if he had clear hands of precum and etc so I'm stressing