Ive had nexplanon implant since 13 on january. my boyfriend and i had sex on the 21 & 22 of january, he finished inside me. should i be worried about pregnancy?

Probably safe: Probably not. The standard advice when starting a new contraceptive form is to use a backup form of contraceptive for the first 10 days to allow your body to adjust to the new hormones and stop ovulating. Since your sexual intercourse was at days 8 and 9 you are probably still protected. To be sure, a pregnancy test can be positive as early as the first day of your missed period.

POSSIBLE PREGNANCY: Since the implant was inserted only 8-9 days following otherwise unprotected intercourse (at presumed ovulation time), you are only in actual danger if the implant was not in place! I would therefore not worry about the possibility of pregnancy unless your period is absent or very light. If that happens, I would see the MD who in inserted the implant.