my initial thought in this matter... well it seems like you might be at risk of a DVT... although due to your history of traveling and discomfort in the calf area are all text book signs and symptoms of DVTs... minus the swelling and the warm or hot to the touch to the affected area... another thing...why are you taking that much ASA in a day... my concern would be for you to become acidotic and cause a change in your PH system. that can also relate to maybe the signs and symptoms of your cramps, which also may explain the bruise on the side of the calf. The whole "pop" that you felt with the relief of symptoms.. that would definately sound more muscular than all...
So in summary
i would say... watch how much ASA you are ingesting a day, u might develop an ulcer..
second of all... how is your dietary intake... u do mention keeping hydrated... being in a third world country an all.
check yourself for any DVT's