After my miscarriage i treat myself for infection with injections and drug i had unprotected sex after the treatment with my husband can i get pregnant before my first period?

Information is incomplete for an accurate answer, but after pregnancy with miscarriage, ovulation may be delayed somewhat, but since "emergency contraception" ("Plan B") is not 100% against pregnancy, and ovulation will occur prior to your next period, pregnancy is possible. If symtoms appear, or your period is significantly delayed, obtain a serum HCG test to be certain.