You might think I'm joking. But I am not. This is such a personal question and it depends completely on what you want out of the relationship. Many people believe that if you want a long-term relationship, you should delay sex until you are both committed to each other.
Another school of thought believes that you should have sex as soon as possible to find out if you have sexual chemistry. Many Americans think that the third date is the sex date, so they might say that two weeks is sufficient time to have shared three meals, watched a movie or a play and go dancing together – and therefore, it's time to have sex.
No right or wrong answer
My point in giving you all these examples is that there is no right or wrong answer; there is simply what works for you and your current sexual agenda.
There are some conversations to be had with new partners though – conversations regarding sexual safety and recklessness.
Does your potential partner have unprotected sex? Have they been tested for STIs recently? Does either one of you have an incurable STI like herpes, HPV, or genital warts? Are you both going to be faithful to each other? Will you both be using condoms at all times? Will you get tested and share your results?
As you read these questions you might come to the correct conclusion that the majority of people do not ask all sexual partner these things. In fact, some couples have sex for months without ever discussing these questions. I brought them up because they should be considered and because I believe you want to conduct your sex life in a more responsible way than most.
All the best and do bring them up with your partner – if only so that you can discuss condom use and fidelity.