I've Lost My Little Nikki, Is there an afterlife? Options

[lostandlonely]

After 14-1/2 years with my beautiful little Nikki - a blue-eyed Siberian Husky - my husband and I had to make the most painful decision of our lives. About a month ago, Nikki became very ill and the vet informed us that the small tumor on his liver that was found a year ago had grown to cover his entire liver and was pressing on his abdomen and other organs. We took him to specialists at Tufts and they confirmed that it was inoperable and we could only keep him as comfortable as possible. Although the list of health problems grew, he seemed to be doing okay and I actually thought by some miracle that the tumor would go away. On Saturday, our whole family went in the back yard to take our family Christmas picture, and he was perfectly fine. On Sunday, he couldn't get up. He stopped eating and drinking. We had to carry him outside to relieve himself. It progressively got worse and my husband begged me to put him out of his pain. I refused still thinking that by some miracle he would get better. Tuesday night, we stayed up with him all night listening to him moan and watching him literally unable to lift his head I knew there was no hope and pleaded with my little Nikki to let go and go to sleep but it just didn't happen. By morning, I just couldn't watch him in pain any longer and brought him in to the vets.

I'm so sickened by what we did and am wracked with guilt. I love my baby more than anything and cannot stop crying. He came with me everywhere and we always planned everything around him. If he couldn't go, we wouldn't go. He was truly my best friend and I miss him so desparately. But now I sit up at night thinking crazy things like how cold he must be outside (where we buried him). Or if he knows we did everything we could. But what is crazier is what's been happening over the past two days since his death. Yesterday while driving on the highway, there was a rainbow in the shape of circle around the sun -- no rain or snow, just partly cloudy. I've never seen a circular rainbow in my life. Last night, one of my Christmas music boxes turned on on it's own. Then at 4:00 this morning I woke up, and as I opened my eyes, one of lights in the window turned on. Tonight my husband got Chinese food for dinner -- boneless spare ribs and chicken were Nikki's FAVORITES, and as soon as we put the food on the table, both my husband and I heard Nikki's tags shake.

We're both very sane people and never thought much about afterlife, but are completely freaked over these happenings. Have others experienced things like this too? I would love to believe he is letting us know he is okay (or telling us we made a huge mistake?), but wondering also if in our intense grief that our imaginations are running wild. Please share any similar experiences or of any books on this subject.