We've had our LO for 10 weeks now, and for the majority of that he would want my OH and always call for 'Dada' (LO is now 9 months). But for the last week it's always 'Mama', no 'Dada', and LO will settle straight away for me, but take a while longer with my OH.
I know things will probably swap again, and that's fine, I'm just enjoying being the one he wants for now!
My OH is the one who gets up in the night, first thing, and spends most of the day with him (he's on adoption leave and I'm working from home, so I'm still there but not as constant), so he is always with 'Dada' but wants 'Mama', so I wouldn't worry too much.
For the first 2 weeks I struggled, a lot, to bond and attach to LO, and he was also scared and more 'aggressive' with his hands and tantrums. I spent more time with him, played with him, and now think he may have sensed my fear. I don't have that now and love him to bits, and he loves me back! 
I think once you're on your own, relax, and spend time with your LO the attachment will come. It is early days!
Happy to PM if you want to chat.