Thickening in left breast with some pain

My doctor gave me a breast exam Feb 2008, which was negative.  I am 66 years and a female.
My psychiatrist started me on Celexa 3 weeks after my breast exam in Feb 2008.

The past few weeks I've had a pain in my left breast when I bend over.  The pain is located on the right lower side.  I also feel a thickening of the tissue there.  There are no lumps or anything under my arm pits or the outer side of the breasts.  The nipples and tissue around are normal, no dimples.

I have read that SSRIs can cause some pain/lump in breasts.

I am not willing to do a mammogram, so I would prefer a sonogram.  Or should I just go for a biopsy?

Do I have cause for concern that these symptoms might be cancer?

[Cleveland Clinic]

Dear Ziera, Breast pain is a common breast symptom.  The reason for breast pain is not clearly understood, and is not usually associated with breast cancer.  Breast pain is sometimes associated with hormonal variations and is then called cyclical breast pain.  Noncyclical breast pain does not seem to be linked to hormonal variations and is often localized to one area of the breast tissue.  Noncyclical breast pain may or may not be the result of an injury to the breast.   Over the internet without being able to evaluate including physical examination it is difficult to say what this is. You should bring your symptoms to the attention of your doctor who can evaluate and put into perspective for you.  

[lil sunshine]

Are you having any other symptoms? I am 46 {soon 47} but I noticed my nipple was inverting lately , a new thing and this got me worried. I went to my PCP and she did a breast exam and is sending me to a BReast Center. I also had calcification last year on my mammograms so she is taking this serious. I am having stabbing pain in the nipple as well.

I hope you get this taken care of, I think we should never take any of this for granted.

Bonnie