Have you been to a doctor for a blood test? It's really the only way to properly detect a vitamin/mineral deficiency. Also, even if you're having symptoms of anemia (tiredness, etc.) it could be something other than iron-deficiency that's causing the problem.
The calcium issue could be described as up in the air at best. There were a few studies in the early 00's indicating that there was no effect, but most were criticized as having too small sample sizes (e.g. http://www.ajcn.org/content/80/2/404.short
, where the size was 14 people), or other inadequacies. There are maybe 20 times as many studies showing at least a correlation between calcium consumption and iron absorption.
@the op...a doctor's visit seems really warranted here. Numerous vitamin deficiencies (B12 and zinc come readily to mind) can also cause tiredness, but so can thyroid problems, viruses, and loads of other issues, many of which could be easily resolved.
It's been a subject of interest to me as someone who works with kids, as anemia in children is quite common and milk is often put to blame. There was some thought (for like 60 years, I think) that this was because the milk replaced more iron-rich foods. That is, kids filled up on milk and didn't eat enough meat, pulses, etc. Then, in the early 90s, there were some studies indicating that the milk itself (and supposedly the calcium it contains) were the problem. The recommendation from the NIH then was to avoid milk with meals. However, there seem to be some indications that it was the phytate/phytic acid that inhibited absorption as opposed to just the calcium. (head spins) I just started looking into this again recently, because my hemoglobin was falling quite low while pregnant, and of course the recommendation was to eat more iron-rich foods. I was already pretty much a protein junkie because of pg sickness/tastes, so I couldn't believe I wasn't getting enough iron. My ferritin levels were fine, in fact, but I still wanted to maximize my iron intake. Anwyay...not to get too off topic, but if you're having a calcium source at every meal, then it may cause a problem.