Brazil Wax baby!

Allie
Hey loves, so my personal preference of how I keep my hair down there looking is, non existent. But I'm still fairly new at the waxing game. I've only done it 3 times, the first two times were months and months apart. But the second and third times were organized and timed correctly. And it was all beautiful, and the hair grew back thin and I was so pleased with the procedure! But after the 3rd time, it few back corse and thick, and FAST! Like two days post wax fast... Has this happened to any of you? And/or do you know why it grew back like that? 
Best, 
Allie Xx