My boyfriend and I had anal sex and then after went on to normal intercourse, can this cause infections?

I am going on a graduation-required 28 day backpacking trip. It is likely that this will happen to fall around my period. What is the best way to work with your period when backpacking? Pads are out of the question, as they are not so great for letting your pelvic area "breathe" during exercise. Tampons...meh. I don't really want to have to carry the new ones in with me (extra weight), or the used ones out with me, like you have to do with all garbage. I thought a menstrual cup would be good, as it can be worn for a long time and there is no garbage involved--however, cleaning the cup might be complicated because polluting is a no-no out in the elements. Maybe I could use wipes of some sort? Are there wipes that don't have body-upsetting chemicals? It would be nice to not have to deal with this for just one month--are there any sorts of short term forms of menstrual suppressors that I could use just one time without huge side effects?

The people in charge of the whole thing don't seem very educated about other options, and simply reassure all of the girls that they can use tampons and carry around all the garbage.

Hi, I'm sixteen and about four months ago I was treated at the hospital for severe anemia due to over excessive menstruation. While I was there, I had to have a pelvic exam done, and I'm already really shy, and I've never been touched like that or even have had a boyfriend. So the doctor (who was a man) was about to do it, but I was so scared he had to physically spread my legs apart. Then he put the speculum in and did whatever, but he had to push through the hymen, and it hurt pretty badly. It seemed like he didn't care at all how I was doing, or anything. Now I cringe when people mention sex or anything like it because it reminds me of him and the pain and embarrassment. How am I ever going to trust a man enough again to let him get close, and how can I block this event out of my head?