not having your shot's exactly 3.5 days apart will have nothing to do with any pain after injecting... i was shooting tues mornings friday nites, but found it hard to shoot b4 work without rushing..(yeah i know i cld get up earlier but i love sleep) so now i shoot late monday nite round midnight b4 bed, and then friday nite right after work... still have the same amount of sides, no big difference..