my lmp was september 17 2016 i had sex with a guy september 16 then again with the same guy september 22 then with my boyfriend sept 29 and oct. 2nd i gave birth june 30th 2017 who s my childs father
Most likely it is your boyfriend.
You had sex with him on days 12 and 15. You'd normally ovulate between days 11-16 of your cycle so you are right in the middle.
You had sex on day 5 with the other guy. Sperm can last up until about 5 days - but that would still be before you'd likely ovulate.
From what you've posted, it's your BF that's the father. A DNA test can confirm.