I managed at the end of the day to get hold of the nurse at the practice who can give test results over the phone. All my results were in the normal ranges except my tsh, which was 5.9 when it should have been below 3 (normal range is about 0.3 to 3) and they prefer you in the lower end of normal when you're pregnant.
This was not a surprise to me - my thyroid levels have always been on the low side and tsh levels high, indicating hypothyroidism. Symptoms of hypothyroidism can include unexplained weight gain, fatigue, depression, constipation due to slower digestion, feeling cold in a room in which others are comfortable, and dry skin and hair. Out of these symptoms i have only the feeling cold, and dry skin and hair, which i've had as long as i can remember. I have had my T3 and T4 monitored previously and they (i think T4, but can't remember) seemed to be moving from below normal to the low end of normal. Looks like i have to get it monitored again.
Low levels of thyroid hormone in the mother can lead to miscarriage or retarded brain development in the baby, so it's important to get it sorted out as soon as possible, as any damage that has occurred can actually reverse if it is caught within a certain time frame.