Leaking...

So I have a 4 month old and I'm 11 weeks pregnant with number 2 tomorrow and my boobs are already leaking.... Like a lot. I stopped breastfeeding my first at a month old so I've been dry for about 2 months now. I was wondering if I could start pumping now and stocking up on milk or should I wait?! I'm not sure if it would cause problems with anything... I was just wondering if anyone had any advice or something!