As you had existing genital herpes before having your baby, the chances of passing it on to your child at all are very low, this is because you already have the antibodies that right the virus, and these will be passed to the baby in utero during the last few months of pregnancy - this protects baby before and for months after birth.
Outbreaks of herpes during the pregnancy also shouldn't be an issue, but the NHS say you could take medication from around 36 weeks to lessen severity of symptoms.
Open sores at time of birth gives a 3/100 chance of passing to baby.
It seems to only be a risk if you have your first ever outbreak of heroes during your 3rd trimester, since your body will not have had the time to make the antibodies to fight of the virus, therefore leaving your baby unprotected too. If this happens, and you have birth vaginally, then the chances are 4/10. Women in this situation would usually have a c-section.
You will be absolutely fine, it seems you have nothing to worry about. Please, don't stress. I have herpes and my pregnancy was risk-free, midwives also weren't concerned. 