I have some serious questions about your argument. Perhaps you can answer them. From what I know of rights, a positive right to abortion would require the state to provide you with abortions if you could not do so yourself. The failure of a positive right to abortion to exist, however, does not indicate that there is no negative right to abortion.

For example, you have a negative right to life, liberty, and security of the person. These are widely recognized as negative rights and I need not dispute this. Now, this is what is important: you do not see people arguing that a lack of a stated right to not be shot in the head is indicative that there is no such right. Somebody would respond to such a suggestion by saying "of course you have a right to not be shot in the head, because it is obviously included in your right to life."

I would like to point out that even if the Charter specifically outlined a "right to not be shot in the head", such a right would nevertheless remain a negative right, because the right does not entitle you to any benefit being conferred by the state, as is required to establish a positive right.

In the same manner, it would be problematic to suggest there is no (negative) right to abortion. Although R v Morgentaler has several opinions which fail to overlap, if (and you may not) accept that the right to security of the person encompasses a right to not be subject to bodily interference, and abortion is such an interference, than you must accept a right to abortion. Lest you choose to say you do not have a right to not be shot in the head.