Would i get pregnant on the first time if my boyfriend has low sperm count ?

Possible: There are many variables but yes it is possible. If trying to avoid pregnancy it is best to use prevention such as condoms, etc. A pregnancy test is always a good start especially if you refrain from sexual activity and repeat the test a couple times over a week or two

Definitely possible: It may be possible. It depends on how low sperm count is and other fertility factors. Only one sperm is needed, the lower count decreases the likelihood slightly. Sex without contraception and 4 days before and leading up to and including the day of ovulation increases your risk. (Most fertile period).