Is God Calling?

I have a heart for missions - or I have had in the past. I've been on 5 mission trips, but it's been almost 9 years since my last one. The first was in 1992 and I went with my youth group to Bryan/College Station and we did simple home repairs on 3 houses in the community - simple things like painting and such. In 1996, I went to Costa Rica and we repaired and painted a church as well as played with the kids. In 1997, I went to Honduras and my team worked at a school, in a medical clinic and one day I even got to handle a machetti and go to work in the rice paddies. I went to Europe for a month in 1999 on a 2 part trip with a team of 8 from Southwest Texas - in England we helped a church with their inaugural VBS, did some homeless ministry and did some street teaching and then in Scotland we were counselors at a youth camp. The last of my 5 trips was in 2001. I went with a wonderful group from a church in Pennsylvania (none of whom I knew) to Russia and we spent 2 1/2 weeks repairing one orphanage and visiting numerous others to visit with the children.
I don't ever remember truly seeking God's will for whether or not to go on any of those trips, but He taught me much and blessed me greatly through each one of them.
I was talking to a friend from church last Sunday about a trip she is leading to Bangladesh this coming June. As she was telling me about the trip plans and what all the team will be doing, I felt a stirring in my heart - a desire to go with them. I've had other opportunities over the last 9 years, but I haven't truly felt a desire to go (or I did, but only because I wanted to see that place - like Zimbabwe or Tanzania).
So, I'm wondering and praying...this stirring in my heart...is it ME just wanting to go or is it GOD calling me to go? Hopefully it's clear soon. She needs an answer yesterday but told me to let her know ASAP!