i don't really see the purpose of harvesting early.. depending on how far into flower it is now, you might not even end up with seeded bud as seeds can take at least 2 plus weeks to start to form a good bit that you'd notice..
also, if it's your only plant, i'd let it go as well.. even if you have more plants going, the worst thing that's going to happen is you get a seeded crop.. there's no evidence that supports seeded bud being any less potent than sensi, unseeded bud, so i'd more than likely just let it ride..
or, one last option, you could carefully pluck any and all nanners that you find.. sometimes a plant will throw a nanner or two, and if you pluck them, they won't grow back.. sometimes they'll continue to grow back after you've plucked them too, so you never really can tell..
harvesting early is a complete waste imvho.. premature bud is dreadful, again, imvho.. after all the time and effort and money you put into a grow, it's really not worth it to chop down early as premature bud will not be anywhere near as potent as bud that went to full maturity..
so yeah, if you have more than the one plant, you can either chop the hermie, of you can leave it and just know that you run the risk of a seeded harvest, but again, seeded bud is no less potent than sensi, it just has seeds in it, not a huge deal imo if you're not planning on selling it.