Because we all have different genetic makeup's and lifestyles, everyone's body will react different to a similar diet and exercise regime.
From my experience, the best indicator of the safety of your routine are your results. If you are experiencing rapid weight reduction then this may be unsafe from a medical standpoint. Excessive weight loss in a short period of time may lead to a number of medical complications including gallstones, elevated blood pressure, high cholesterol, coronary heart disease, increased long-term weight gain, binge eating, reduced physical activity, reduced energy expenditure, increased hunger levels, altered hormone levels, changes in substrate utilisation, increased fatigue, increased disposition toward fat storage and depression.
Have a read of Yo-Yo Dieting - No-No Dieting which goes into a bit more detail about rapid weight loss.
Also assess how you feel. If you are feeling particularly lethargic and run-down, or experience mood swings, then this could be a clear indicator that you are not recovering effectively. Inhibited recovery can often be a result of excessive exercise and/or limited dietary nutrient intake, amongst other things.