can i get pregnant if my partner didnt cum in my vagina but on his hand and didnt wipe the cum off his head and he just sticked it back in me ?

Hi loralush,
Thanks for your question and for finding EmpowHER.
Any time your vagina comes into contact with semen without the use of some kind of birth control, you are running the risk of getting pregnant. Here are several lengthy threads on the subject of fooling around and if you can get pregnant without penetration (intercourse/sex). Hope it helps:
https://www.empowher.com/search/google?cx=007544384767083790728%3A2otat3sg2a8&cof=FORID%3A9&query=can+you+get+pregnant&op=GO&form_build_id=form-74f15ebfaaf5166e253cc42568fab22e&form_token=0fafb374ad931da4e234eee767a5882f&form_id=google_cse_searchbox_form
If you decide to continue to be sexually active with your boyfriend, you may want to look into protecting yourself from STDs and unwanted pregnancy:
https://www.empowher.com/pregnancy/content/which-birth-control-most-effective
https://www.plannedparenthood.org/all-access/my-method-26542.htm
Have fun, but be safe.
Good luck and let us know if you have any more questions.