How long can sperm live inside you ? And how many DPO should I wait to test ?

I’ve read 5 days at max?

My husband and I had sex 3.5 days before I ovulated and that’s the only time we did it during my fertile window... I’m going crazy during this two week wait and feeling like my chances are low since we only did it once, but we wanted to try the Babydust method for girl sway and now I feel like we should have just done it more to try and conceive in general 🥴

Also, how many DPO can I test? Is 8 DPO too early ? I’m 4 DPO today and literally going crazy symptom spotting 🤦🏻‍♀️😭

🙏🤰🏻💞