Google visits your blogs or web site frequently. The frequency of visiting on a particular blog or web site depends on many factors like visitors traffic, contents quality, web site page rank, how frequently the contents updating.
Google comes every hour or many times on a day on a web site with high page rank, high quality and frequently updated contents while comes in a month on a web site which having low page rank, less visitors traffic and poor contents.
How to find when Google crawled your web site recently?
To find out this please follow below steps:
Step -1. Just open google.com
Step-2. Search your site, for example ajittiwari.com
Step-3. Click on “Cached” link
You can see the date and time in above red circled area, this the latest date (23 Jun 2013) Google visited on the site.
Now check your own site and let me know if you need help, thanks,