What Does This Following Blood Report Indicate?

Question: Recently I had knee surgery because I had a necrotic defect in my knee and it broke off into 6 pieces and the had to remove the loose bodies. When I was talking to the physical therapist they asked me about pain. I told them I have a lot of bone pain. Especially at night. It is the worst in my upper legs/especially knees and upper arms and elbows. It is a deep ache. I have a history of chronic pain in muscles and sometimes joints, but this is different. Its been consistent for 2+ months. The PT said they ask about pain at night because that can be a sign of cancer and that I should mention it to my doctor.
1. I was just curious why cancer causes night pain?

Also, about 2 years ago I was diagnosed with low ferritin. My doctor tried iron infusions but I got sick from them. He said my other iron levels were fine, just a low ferritin. Is this a concern at all if my other numbers are ok? What causes only the ferritin to be low?
Below is a blood smear from a year ago. Is anything abnormal/concerning on here? What is rouleaux formation?

Peripheral Blood Smear:     Red Blood Cells: Normocytic, normochromic. Few ovalocytes and mild rouleaux formation.
White Blood Cells: Decreased in number. Monocytes with cytoplasmic vacuolization.
Platelets: Normal in number, few large giant forms.
Impression: Mild anemia and leukopenia. Correlate with serum protein studies.


This is my most recent labs from March

WBC     2.9 10E3/uL     4.8 - 10.8 10E3/uL
RBC     3.74 10E6/uL     4.00 - 5.40 10E6/uL
Hemoglobin     12.2 g/dL     12.0 - 16.0 g/dL
Hematocrit     35.7 %     35.0 - 47.0 %
MCV     95.5 fL     80.0 - 99.0 fL
MCH     32.6 pg     27.0 - 34.0 pg
MCHC     34.2 g/dL     31.0 - 37.0 g/dL
Platelets     234 10E3/uL     130 - 400 10E3/uL
MPV     9.3 fL     8.0 - 13.0 fL
RDW     12.3 %     11.0 - 16.0 %
Neutrophil Percent     44.7 %     37.0 - 75.0 %
Lymphocyte Percent     42.7 %     14.0 - 48.0 %
Monocyte Percent     7.5 %     0.0 - 12.0 %
Eosinophil Percent     4.4 %     0.0 - 6.0 %
Basophil Percent     0.7 %     0.0 - 2.0 %
Immature Granulocytes Percent     0.0 %     0.1 - 0.3 %
Neutrophil Number     1.3 10E3/uL     2.0 - 8.0 10E3/uL
Lymphocyte Number     1.3 10E3/uL     0.7 - 5.2 10E3/uL
Monocyte Number     0.2 10E3/uL     0.1 - 1.3 10E3/uL
Eosinophil Number     0.130 10E3/uL     0.150 - 0.300 10E3/uL
Basophil Number     0.020 10E3/uL     0.000 - 0.210 10E3/uL
IMM GRAN Number     0.00 10E3/uL     0.01 - 0.03 10E3/uL

Ferritin     6 ng/mL
Iron     132 mcg/dL     50 - 212 mcg/dL
Transferrin     269.0 mg/dL     203 - 362 mg/dL
Iron % Saturation     39 %     15 - 50 %
TIBC     336.25 ug/dL