The most common symptoms of gastritis include: (13) 1  burning sensations in or above the stomach/abdomen, especially around the time of eating. 2  stomachaches or pains. 3  nausea or vomiting. 4  stomach bloating. 5  loss of appetite, feeling very full quickly and possibly experiencing changes in weight. 6  hiccups and burping.
For the most part, taking birth control while pregnant will not cause your baby any harm. This is especially true if you have been using birth control pills early in your pregnancy. But, if you have an IUD and become pregnant, you may be at risk for certain pregnancy complications.
Now, as for your question about when to start taking oral contraceptives, there's really no hard-and-fast rule about when to start taking birth control pills. Starting in the first few days of your cycle is the surest way to prevent inadvertently taking pills while you are pregnant.