People have been welcoming and not sketchy at my local meetup. I look forward to going there. I'm pretty constantly aware that I'm the only or one of the only women there, but I don't feel that other people treat me differently because of it. Sometimes I enjoy the gender ratio. My college and most of my jobs were mostly-female, so being in a mostly-male space is novel and interesting. But I also really enjoyed it when a new woman joined the meetup, because it was nice to feel there was someone a bit more like me (female, with good social skills, smart but not a programmer/scientist).