I’m genuinely so fucking scared I’m on the nexeplanon but I genuinely think I’m pregnant?

I have regular sex without a condom (in a relationship) and I know birth control is normally 99.9 % effective

But I’ve started brown spotting and my stomach feels super bloated should I take a test?...

Last time I had sex was last Monday then two-3 weeks before that

And before that obviously<<< but I’m genuinely so scared