oil by oil filter

ok guys i put new oil filter and oring in aswell and then tightned up the bolts on cover i cleaned off all the old oil from around engine wher it ran out when taken filter out…its been bout 4 months ago i done this.other night i noticed looked wet around the cap so i rubbed my hand and ther was clean oil around it,i wiped it dry and day after ther was none still but when i started it left it run for 5 mins and rev few times engine was hot i turned it off and ther was oil around it agin not a lott but a small bitt only just damp its not dripping or anything…now i must admitt i have bitt too mutch oil in when i dipstick it would that cause it and should i take out some?
how would i manage that without draining all the oil?thanks