Coconuts are considered very auspicious for many amazing reasons. It has great nutritional significance. During every visit to a temple or during every puja, we take coconuts and break them near the lord. We offer the coconuts to the lord and then have it as prasadam. We have the water inside the coconut as a theertham or holy water.
Coconuts are like every other fruit that sometimes gets spoilt in the inside. We do not even know it is so until we break it open. So it is always advisable to consider anything as a good sign and leave it to god. Sometimes due to unevenness or due to extra skin on the nut, it doesn’t break in the correct form. This also doesn’t mean anything wrong.
It is only wrong to encourage such thoughts and continuously take tension over it. Whatever happens, happens only for the good and nothing bad. God has always taught us just this.