Suppressive therapy means every single day, not every 3 days. Either you take it daily, or don't bother. It will have no effect if you take it every 3 days.
Since its clearly bothering you that you didn't tell her, from now on, tell.
Aj
Below is an answer Grace - the moderator for this forum had posted to a male a while back with a similar concern:
"If the male is hsv2+ and the female isn't - if you do nothing (meaning no anti-virals) but AVOID sex whenever the male has obvious genital lesions - the female has a risk of about 8-10% each year of contracting hsv2. If the male is on daily suppressive therapy the risk is cut in half which makes it about 4-5% each year. If you throw in condoms along with all that it's a 2-3% risk each year of contracting hsv2 from the male. This info only applies to valtrex, not to acyclovir or famvir ( valtrex is not yet available in most countries as a generic - only in india and it can't be legally sold outside of india ). They have not studied this ( and published it ) in the other 2 herpes antivirals to compare them."
I don't know though if this fully applies to you because it wasn't clear if you were having an outbreak at the same time as you had sex . Also the quote indicates DAILY suppresive therapy and you indicated every three days or so..
Hopefully, Grace will post to add.