How would I find the period of a system of ODE's at a given parameter point 'p'.

The system is:

dx/dt = - x + 0.1*y + x^2*y

dy/dt = p - 0.1*y - x^2*y

I am looking to find the period of these two ODE's at any given parameter point 'p'.

If that is not possible could someone help me find the period of the system of nonlinear equations at any parameter point 'p' where:

f1 = - x + 0.1*y + x^2*y
f2 = p - 0.1*y - x^2*y

Thanks for any help