condom asociated with failure, pregnancy may be expected?

( i had sex on 8 feburary n my partner had used condom aswell.. is still there is chances of pregnancy n bacterial infection or sexually transmitted disease? )doctor replied me that condom are asociated with failure and pregnancy may be expected.. but i had no missed periods after having sex i had just one or two dayx delayed periods but not missed in this following months march ,april, may and june...... is still pregnancy is expected. because i felt no spotting since having sex on 8 feb. i observe light brown liquid after periods for the first time in 4th month on 19 june.