OP this is normal. don't listen to these other guys they are uninformed. typically testicular ache should fade after a week or two. in the private forums tons of guys report that this side effect is how they know it's legit RU. i've just started RU myself two weeks ago and had the same side after a week, now it's fading. you should be fine.
just make sure to keep your RU dose between 40-100mg and preferably as low as possible in that range. it's very effective in small doses, many use 40-60mg and completely stop their loss. don't go above 100mg a dose as it's just superfluous.