When should I take a test

My nexplanon implant came out 22nd March after being in for 2 years and I've been on no birth control since then as my partner and I are taking a "if it happens it happens" approach.

I'm on day 19 of my cycle and we have unprotected sex at least once daily. I've felt nauseous for the past 3 days, but this is the only thing I've noticed that's different. TMI but my partner says I feel different during sex, tighter?

I'm a big lover of coffee but the past 2 days I've struggled to drink it as it tastes different, but I couldn't put my finger on what was causing my coffee to taste so bad.

My partner has told me to take a test, but I think it's too early. When should I take one? If at all