Pregnancy Gingivitis: This condition is common during pregnancy due to hormonal changes, particularly the increase in progesterone levels, which can exacerbate the body's response to plaque, leading to inflammation and swelling of the gums. The patient's symptoms of gum swelling since the first month of pregnancy align with this diagnosis.

Aspirin-induced Gingival Enlargement: Although less common, long-term use of aspirin can contribute to gingival enlargement. Given the patient is on aspirin 75mg nightly, this could be a contributing factor to her gum swelling.
Poor Oral Hygiene: Inadequate dental care can lead to the accumulation of plaque and tartar, causing gum inflammation and swelling. This is a common issue that can be exacerbated by pregnancy or other factors affecting oral health.
Vitamin Deficiencies: Deficiencies in vitamins such as C or B12 can affect gum health, leading to swelling and other oral health issues. Pregnancy increases the demand for certain nutrients, making deficiencies more likely if the diet is not well-balanced.

Leukemia: Although rare, leukemia can cause gum swelling due to infiltration of leukemic cells into the gums. This condition would be critical to identify early due to its severe implications for health.
HIV/AIDS: Gum swelling can be an early sign of HIV infection, which is crucial to diagnose due to its significant impact on health and the importance of early treatment.
Diabetes Mellitus: Uncontrolled diabetes can lead to gum disease and swelling. Identifying and managing diabetes is vital for overall health, especially during pregnancy.

Sarcoidosis: A rare condition that can cause gum swelling among other systemic symptoms. It involves the growth of granulomas in various parts of the body.
Wegener's Granulomatosis: Now known as Granulomatosis with Polyangiitis (GPA), this is a rare autoimmune disorder that can affect various parts of the body, including the gums, and cause swelling.
Ehlers-Danlos Syndrome: A group of disorders that affect connective tissues supporting the skin, bones, blood vessels, and many other organs and tissues. Some types can lead to gum recession and other oral health issues.