Thanks for query,
We have 2 ovary & 2 fallopian tube
both sides of uterus
We get ovulation & ovum traveled through fallopian tube to get embeded in uterus after being fertilised by sperms.
2 has more chances but still you have one so your the probability is reduced but not zero.
Only one chance required to be pregnant may be your next ovum.
So nothing to worry,
Your Doctor had rightly said keep on trying.