Fermentation still going after 10 day dry hop - do I bottle anyway?

This is my first all grain batch - a 3-Floyds Dreadnought clone. Unlike my last 2 extract kits, this one is fermenting like a MF. This time I used two viles of yeast, yeast nutrient, and aerated the wort with a pump - so that may be why. Anyway, after fermenting a little more than a week, I hit the target gravity (almost 9%) and it looked like it was done (in a bb bucket), so I moved it to the carboy and dry hopped it. Of course, once it was in the carboy, the seal is much better and it's been bubbling steadily for the last nine days. After 10 days, tomorrow, I am supposed to bottle it. Is that safe? I've never had this problem before, so I'm not sure what to do. I put a lot of time into this batch and I'd hate for it to end with exploding bottles.

Take a gravity reading today and then take one until the batch stabilises. As you say you dont wantto risk bottle bombs. Yeast doesnt work to a schedule so your timings should be taken with a pinch of salt

Airlock activity is not a good indication of yeast activity. It's possible (probable) that you're seeing CO2 escaping from solution, especially with all the nice nucleation sites that hops provide. As Andrew says, look for a stable SG reading.

Pretty much have to echo the above, airlock activity is a good indicator of gas going through the airlock and nothing else. Check the gravity, if it is stable and you've hit your dry hop timing you are good to go.

Thanks guys - that's what I needed to hear. Airlock activity doesn't mean fermentation is happening. Stable gravity is what tells me it's done fermenting.

there is NO timetablele for yeast, no matter what the instructions say. hydrometer readings of a stable gravity is the only way to know for sure.

Judging from your post, it could be that it wasn't done fermenting yet when you moved it to secondary to dry hop. always be sure it's done fermenting in primary before racking anywhere.

It dropped from 18 to 16 on the rack (target FG was 21), so you're correct. I went ahead and bottled it because it appeared to be done fermenting and I didn't want to over expose the beer to the dry hops beyond the 10 day limit.
I won't make that mistake again. I have this irrational fear of spoiling my beer, so I don't take enough hydrometer readings. I will make sure to take readings for a couple days before I rack/bottle from now on. I appreciate everyone's feedback. I've been brewing solo, so it's nice to have a place to get quick answers from the pros. It tasted close to what I was expecting when I bottled, but I'm still fearing explosions. It seemed a little sweet...

Generally if the yeast is within it's allotted attenuation range then it's probably done fermenting so a target FG isn't always the best measure unless you have used a yeast a lot and know how it behaves. Transferring can sometimes cause fermentation to start again but isn't necessarily all that common. On bigger beers sometimes the yeast can kick back in and finish up what they were too lazy to do in the initial primary ferment. You are probably fine but just something to be aware of. If you want optimum performance of your yeast then a starter would be a good idea.

As a followup, it's been in the bottle for 2 weeks and is barely carbonated. I've read I need to just wait longer or add a little yeast to each bottle. In this case, I think I'll just wait and pray for the best. I guess that means it was definitely done fermenting. I'm learning a lot with this beer. I opened one last night and it tasted pretty darn good for flat beer, so hopefully it will carb up in the next couple weeks.
Ah, another thing I learned - dreadnought makes a nasty beer milkshake. My kids were making milkshakes and I decided to throw the rest of my flat beer in there. Yuck - drank it anyway though. Can't let it go to waste!