Break ups are hard. Having our belongings returned or retrieving them is one of the niggling things that can either expediate or prolong..... or even prevent closure. I think if it were me, I would contact the ex and arrange a specific time for him to drop off or for you to retrieve your belongings. Should you feel uncomfortable seeing your ex again, its probably wise to have a friend with you to mediate the exchange. Allowing too much time to go by will only make it harder...and I fear if you wait too long you may never get your belongings back.