Is it me or what?

I'm 29 years old and have a 7 year old boy and I don't really remember what happened once I got pregnant since with him I didn't find out I was pregnant with him until I was 2 months along! So after I had my first and hopefully my last miscarriage 2 years ago, that it has been very hard to try to have another baby, it seems like I will never get pregnant again! Well on here I'm not due for af til tomorrow but it doesn't ever come the same day! For the longest time I have mostly went to the doctors and only be weighed 104 and now all of a sudden a few days ago when I got weighed at my doctors appointment, I was 107 and found out today that I can't fit into a few pairs of pants that I used to and it got me wondering if it's just me or could it be? Oh and I'm a very small woman and look like the same size of a teen so it's not normal for me to be gaining weight as easy! What do yall think?