Anytime you have unprotected sex, there is a risk of pregnancy. You decided to have unprotected sex twice consecutively, which is also a higher risk of pregnancy.
Pre-ejaculatory fluid ("pre-cum") does not contain sperm itself, but it can push up sperm that is still inside the penis from a previous ejaculation. Since your boyfriend ejaculated, then had another erection and inserted his penis back inside your vagina...there is a possibility of sperm coming into contact with your vagina under this circumstance.
It does not really matter how proud you or he is of his "timing" of ejaculation...I am surprised that you were finding this as a way to congratulate him, instead of either of you insisting on wearing a condom if you do not want to become pregnant.
Please use a condom every time you decide to have sex, or his erect penis is near/on/touching/beside your vagina.