Yes its safe. Youre safe all month long. What makes your period come is the withdrawl of hormones from your body.

<3
gaby

If theres no ovulation, is the egg still released or do they just build up?

The egg is not released. Here's why.
Every baby girl is born with thousands of inmature eggs already in her ovaries. In fact - she is born with every egg she will ever produce (odd isn't it- thinking you're walking around with your future children's dna already in you!). Around puberty your body starts releasing hormones telling the inmature eggs to mature. Once a month one (or occasionally more) egg will reach maturity and be released. This is ovulation. When you are on the pill, the hormones you ingest prevent your body from telling the egg to mature, hence it is never released. The eggs stay in your body untill you stop bcp and allow your body to chart it's own course.

~laura

Eggs don't build up. When you are approximately 12 weeks old in the womb you already have all the eggs you will ever make.