Abnormal behavior of SQL%ROWCOUNT

In a function I have used SQL%ROWCOUNT after INSERT statement to ensure how many rows inserted but some time it works and some time  it don’t . I have wrote 2 INSERT statement one after another and used SQL%ROWCOUNT after 2 ^nd INSERT to ensure row inserted into 2 ^nd INSERT statement. But some time I only found row in only 1 ^st INSERT. Please guide.