Pregnant? with yearling still attached

Question
I am wondering if my mare is pregnant? b/c she is starting to gain weight and i live on a ranch and ride her about 4 to 5 hours a day.  she is her yearling is still sucking so i am not sure if she will bag up or if the yearling is sucking it all out? she has been acting funny like lying down in the lake and her diet has not changed.  she went from a little skinny from winter to plump.  however she dose not have a huge belly but she didn't the last time until two weeks before birth.  a stud got in about 15 day after she gave birth last year.  but i don't know if she caught. do you have any advice?

Answer
Ashley:

there is no way I can tell you if your mare is pregnant over the internet. You need a vet to examine her. A simple rectal exam is all that is often necessary. Your yearling should be weaned by now. I strongly recommend you do that before -if its a male- it can breed the mare. Looking at body size and condition is a completely unreliable way to evaluate for pregnancy. Get a vet to look at her if you need to know this. I cant do it over the internet or based on any descriptions you give me.