no period 3 1/2 mos., eating disorder, can I get pregnant?

Hi,
Welcome to ehealthforum,
If you are having long gaps between periods, it could suggest anovulatory cycles (menstrual cycles without release of egg from ovary) which usually occurs during pubertal stages. Other possibilities include PCOS, ovarian suppression, hormonal derangements, etc. The exact cause can be made out only after careful evaluation. Consider visiting your doctor/gynecologist for thorough examination and further evaluation to look for the underlying cause. Treatment as appropriate (based on examination findings and investigations results) would be started to help you regulate your periods. If you are not ready for pregnancy, but intend to become/remain sexually active, you should consider visiting your gynecologist to get started on suitable regular birth control measures to be protected (after your periods). Be regular with birth control use as instructed. Avoid having unprotected sexual contact if you are not ready for pregnancy. Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest. Maintain healthy diet and lifestyle.
Take care.