My neck hurts form trying to elevate my head at night, can i take an anti-acid instead?

Yes: Antacids like Tums are a good choice for heartburn in pregnancy. They neutralize the acid and are good when you have the symptoms. If you have to take them often though taking a preventative medicine daily will be helpful. Omeprazole, Prevacid and Zantac (ranitidine) are good choices. These prevent heartburn before you feel the symptoms.

Perhaps: I assume from your question that you're elevating your head at night to try to reduce gastroesophageal reflux (gerd). Other non-pharmacological methods include avoiding eating close to bedtime, and staying away from certain foods like chocolate, caffeine, alcohol, tomatoes, and spicy foods. As long as there are no contraindications, antacids and other types of acid blockers can also be helpful.