One thing to consider with your situation is the amount of activity you did have after your aboriton. After an abortion it is pretty common to have more bleeding if you are more active, or if suddenly start activities soon after an abortion. You went on vacation, so your body definately did have some stress associated with travel.
Since you were on the pill for 1 week, you were protected from pregnancy =) the bleeding and spotting pattern you had on the trip could be from a combo of using the pill, taking ec, and having the abortion.
Anytime you have pains, you shouldc ertianly seek the advice of your doc. It could have been from your trip, and the activities which you would have participated in.
Usually women are told to take it very very easy the first week-2 weeks weeks after an abortion.
Hvaing sex soon after an abortion can cause an infection, but you would have a higher fever associated with an infection. You would have noticed an infection, I am sure of it...