Is it my blood type? Is it hormones? Ist it our sweat?

When my mother died and her funeral was held four years ago (around this same time of year) I was attacked by horse flies at the wake and bitten 72 times (mind you that I was an only child and attacked by horse flys at my mother's funeral), one other person was bitten once... apparently bugs love me. Four months after my mother died I was pregnant with my son who just turned three this past July. Most recently I was a bride's maid in my cousin's wedding whereby I was attacked by a housefly repeatedly that left everyone else alone. When I got home that evening my son had 29 bug bites (counted as I put calamine lotion on each) while he was staying at a relative's house that lived out in the country, by the way they do look just like the horse fly bites that I remember from that horrible day. Why us? Why flies? Is it our blood type? Our hormones? Our sweat (in August)? Why do flies love us?