I'm sure you're fine.. I'd do a small water change just to make me feel better, but if everything is at zero, there's not really a need.
I fishlessly cycled a 125g tank recently - I waaay overdosed with NH3
up front (normal household kind, no perfumes/surfacants.. a 10% solution) I put 1.5 CUPS of it into the water at once.. holy sh*t that stunk, readings were WAY off the chart.. so I waited and waited.. after 6 days the Nitrites had spiked.. another 3 days later NH3
was at zero, N02 was going down.. 10th day my tank could completely convert to N03 approx. 6ppm of NH3
in 8 hours.. (yes overkill) Kept "feeding" it NH3
until my fish order arrived from Armkes.com.. approx. 30 small-medium sized cichlids. Did a 60% water change (Nitrates naturally were off the chart) which brought the Nitrates down to about 10, added the fish and they've been happy since, everything consistently reads at 0ppm.. ('cept N03 of course, no plants, so a 15% weekly change keeps that in check.)
(I should note, upfront I also added approx. 10lbs of lava/tufa from an established tank and ~1gallon of "filter mud" (I empited my Fluval 304 from the established 55g tank directly into the 125g tank).. I'm sure that helped..