I've only used a condom once and that was when I came off the mini pill and started taking the combined pill (the pill takes a week to become effective, so we used a condom then).
It's a personal decision. The sexual relationships I've been in have all been monogamous. I lost my virginity without a condom (I was taking the contraceptive pill). The guy was a virgin too, so no STDs to worry about. Other guys, I've requested full STD tests (and provided my own results). Might seem over the top to some people but STDs aren't something you want, especially as some are incurable. Guys were cool with taking tests; sometimes you don't know when you have an STD (as with chlamydia). Testing is quick and easy. Switching sexual partners = STD test.
If I had a one night stand (no plans, but speaking theoretically), I would definitely use a condom because you haven't got to know them well enough, there's not enough time to get a conclusive STD test and, unfortunately, people do lie about what they have and haven't got.
Guys say that bareback feels a lot better than with a condom. As a girl, I personally feel the same way. It also feels more sexy and there's the added benefit of the guy being able to pull out quickly and come wherever I want it.
I take my pill at the same time every single day (I skip the pill-free week every month). I have an alarm on my phone to remind me. I set a reminder on my phone's calendar two weeks before I'm due to run out of pills so I can book an appointment at my local sexual health clinic and pick up more pills (I go every 18 weeks). I have never had an unplanned pregnancy - or even a pregnancy scare - since I started having sex. The combined pill is more than 99% effective when taken correctly; condoms are 98% effective. So, provided you take the pill correctly (which surprisingly a lot of girls don't), you are extremely unlikely to get pregnant. I do keep a pregnancy test in my drawer just in case. I have never once needed to use it.
Despite everything I've said, I am not against condoms. I don't hate them. I'm a firm believer in people being safe. When I go to the sexual health clinic to get my pill prescription, I get free condoms as well. You never know when you might need one (forgotten pill, antibiotics reducing effectiveness of pills, vomiting cancelling out effects of the pill, etc.)... or if somebody else might need one!