Too soon?

I had unprotected sex the 13th- five days before ovulating and since then have felt so sick. A week after I started having heartburn for two days straight- could’ve obviously been from something else. I just never get heartburn! I know it’s way too soon to have any symptoms, but I can’t take a test anytime soon- March 11th at the earliest due to I’m currently being a live-in nanny for my sister and there would be no way to have any privacy when it comes to taking the test let alone buying one. I’m hoping my body just feels differently from being 13+ hours from home for the next few months, and that I’m not currently pregnant, yet.