Had opportunities from 15-17. But I grew-up in a conservative area and went to a Christian private school, so I was taught to value virginity. I wasn't one of those "saving myself for marriage", but I chose to hangout at 3rd base for awhile until I felt I was ready. There were plenty of people around me having sex at that age, but I'm pretty much immune to peer pressure, so I just went at my own pace. Got to 3rd base a ton in mid-teens and some of the girls wanted more, but I declined. Eventually did the deed at 18 with a serious girlfriend.
I think it's important not to rush into it where you feel uncomfortable. You should do it when you and your partner feel ready, whenever that is. And at the same time, sex and virginity shouldn't be put on a pedestal. It's something you should do responsibly (irresponsible sex can lead to STDs, unplanned pregnancies, mental stress, etc). But driving a car is also something we should do responsibly, so we handle all kinds of responsibilities every day. Unless you have specific religious or personal reasons why you want to remain a virgin, if you're over the age of 25, I'm a believer in just finding a "professional" and just doing the deed. Just so you realize that sex isn't some ethereal event and help reduce some of the pressure and anxiety. A long time ago, I had a co-worker who was 23 and struggling with anxiety and everything when it came to women. He saw an escort and he was a completely different person afterwards. It didn't solve all his problems or anything, but he was just way more relaxed and confident around women now that he wasn't putting sex on a pedestal anymore. That said, don't take some random Internet forum poster's advice, therapy is always a great option if you're a late-bloomer. Just food for thought.