Trying to conceive twins

I'm a mother of two. 3 yr old baby girl and a 2 yr old son. I'm trying to conceiv twins, but no twins on my side of family but my husband side has twins, anyways I'm 21. I don't want to spend money on getting a IVF. I want to know if any of you mothers out there conceived naturally and without having twins on your side of family.? Please and thank you..