Plz help! Question about anemia & hemoglobin count...?

I am a 44 year old female and live in Canada. A year ago I had a hysterectomy and my hemoglobin levels dropped way down to 76. My stomach was unable to tolerate iron supplements so it's been a slow process trying to build my levels back up. About 10 or 12 weeks ago I had my hemoglobin checked and it was up to 112, but I when I had it checked again last week it had dropped to 105. Is this a cause for concern? I don't know how significant of a drop that is but considering I no longer get a period, and I haven't had anything else happen to make me lose blood I can't understand why it would drop. I am so sick of being tired all the time and just wonder if this is something I should get checked out or if it's just a normal fluctuation....