id say around day12? why do u think u aint O? u shud get some opk and start doing them around day 10 so that u defo dont miss getting a pos on the opk, think with all that sex it b wierd if u werent preggers!!!

good luck and keep posting to let us know,think u shud defo get opk test though,av a look on ebay u can get about 10opk n 5hpt for £2.50 n £2.50 p&p, i get them n always arrive next day,i aint tried these ones yet but loads av recommended them!!! good luck, hope we both get a bfp this mth!!