I pulled Romex wire from my main box to my sub box but the wire only has black, white and ground wire. From everything I have read u are suppose to have a red wire. Can I still wire my 70amp aub panel without the red wire?

How many volts are you running to the sub, 120 0r 240?

You can but it's totally not worth it. Having a 120v only (or 240v only) panel makes no sense and will likely cause a dramatic imbalance of your service.
Besides, finding a 70A SP breaker is not going to happen, and using half a 70A 2P is just wasting space.

Why did you pull only a 2-wire?