At this stage of the game 38+ we never know when it's the last fresh egg in the carton so I would tend to have you in with attempt. What if it is a "golden egg" and then you don't get another good one for 3 or 4 more months, yk??
1 cup of milk is certainly within LE Diet tolerances and I wouldn't worry about that. Magnesium, I do not think sways much in isolation. Unlike Vit. D and the B's - which I think DO sway pretty strongly all on their own - the mag alone, I'm not convinced is very overwhelming a swayer.
THe day to attempt is at your discretion, I'd have you in on first day of solid smiley (this translates to day of pos OPK). Timing doesn't sway, but the one attempt does, and that day of first solid smiley is a good chance of conception with one attempt. We are getting 10% lower results with 2 attempts than one.
I'm not recommending aspirin any more because our numbers have not been that outstanding and there may be some safety concerns (new study linked it to heart attacks in women) and I never give 44 year old men LR. :)