Yes, one should recite: “A`udhu bi Kalimatillah At-Tammati min Sharri ma Khalaq.” when entering a new home. This supplication seeks Allah’s protection from all harm.

There is no sin in asking someone to make Du`a for you whom you hope will have his Du`a answered, provided that this does not involve anything prohibited. However, it is better and more appropriate not to ask.

The best Du`a to get pregnant in Islam is the Du`a of Prophet Zakariya: ‘Rabbi la tadharni fardan wa anta khayr ul-warithin’. And: ‘Rabbi hab li min ladunka dhurriyyatan tayyibatan innaka sami`Ad-Du`a.’