You can look at the USCIS website for details:
http://www.uscis.gov/portal/site/uscis/menuitem.eb1d4c2a3e5b9ac89243c6a7543f6d1a/?vgnextoid=a0ffa3ac86aa3210VgnVCM100000b92ca60aRCRD&vgnextchannel=a0ffa3ac86aa3210VgnVCM100000b92ca60aRCRD
Here are what I knew by a web search because my friend has similar experience.
- If your husband was an US citizen when you married him, you only need to wait 3 years to apply for citizenship if you are still married with him.
- The important is having continuous residence within the last 3 years, and you are still married with your husband.
- Since you haven't taken trip over 180 days, it does not sound like you have broken the continuous residence rule.
- It wasn't very clear if the rule will apply if you have leave US in 2 trips within a year that is over 180 days. Hopefully, you do not have some back to back trip in your 4 trips. Also, the officer may have question about the purpose of those trips to determine if you consider as resident of other places. If they determine you have been resided in Hong Kong instance of short-term visit, they still have the rights to fail you. (Unlikely, but possible).