Or, look into other options, i.e. birth control that is not daily but rather monthly or quarterly. Or, if your issue is that you "don't see him often" and that makes you forget, get another partner to have sex more regularly (if more than one partner, with condoms) and that way, remember. Or, use your cell phone to ring every day at the same time to remind you. Or, use Google Calendar to send you a daily reminder via email if you use GMAIL. Whatever you choose to do, be inventive, but do something. If you cannot do any of the above listed options and you still foresee having unprotected sex at irregular intervals in the future, you need to pick up a few doses of Morning After Pill and keep them at home or in your purse or wherever convenient and instantly available.

And when eventually you have your first child, get an IUD which fixes this entire problem for 5 years and you won't think about it ever. Given your forgetfulness, IUD is the best option for you. Somebody on this forum actually wears an IUD having never had children, but I do not know about that. Usually, it is recommended for women who have had children.